RayTraceMaterials

gistfile1.txt

using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using UnityEngine;
using Unity.Collections;
using System.Diagnostics;
#if UNITY_2018_3_OR_NEWER
using UnityEngine.Rendering;
#else
using UnityEngine.Experimental.Rendering;
#endif
public class RayTracingMaster : MonoBehaviour
{
    public ComputeShader RayTracingShader;
    public RayTraceSpeed raySpeed;
    public enum skyMode
    {
        none, realSky, hdri
    }

    [Header("Environment")]
    public skyMode theSkyMode;

    public Color backgroundColor;

    public Light DirectionalLight;


    public Texture SkyboxTexture;


    [Header("Clouds")]
    public Color skyTint; 
    public Color groundColor;

    public Texture3D noiseTex1, noiseTex2;

    // public int SphereSeed;
    //public Vector2 SphereRadius = new Vector2(3.0f, 8.0f);
    // public uint SpheresMax = 100;
    //  public float SpherePlacementRadius = 100.0f;

    private Camera _camera;
    private float _lastFieldOfView;
    private RenderTexture _target;
    private RenderTexture _converged;
    private Material _addMaterial;
    private uint _currentSample = 0;

    //private ComputeBuffer _sphereBuffer;

    private List<Transform> _transformsToWatch = new List<Transform>();
    private static bool _meshObjectsNeedRebuilding = false;
    private static List<RayTracingObject> _rayTracingObjects = new List<RayTracingObject>();
    private static List<MeshObject> _meshObjects = new List<MeshObject>();
    private static List<Vector3> _vertices = new List<Vector3>();
    private static List<Vector2> _M_UVs = new List<Vector2>();
    private static List<int> _indices = new List<int>();
    private ComputeBuffer _meshObjectBuffer;
    private ComputeBuffer _vertexBuffer;
    private ComputeBuffer _indexBuffer;
    private ComputeBuffer _MUVBuffer;


    [Header("Capture Settings")]
    public UTJ.FrameCapturer.GBufferRecorder bufferCapture;
    public TMPro.TextMeshProUGUI sampleCount;
    string oldname;
    public bool shouldRender = false;
    public int qualityDivider = 8;

    Queue<AsyncGPUReadbackRequest> _requests = new Queue<AsyncGPUReadbackRequest>();

    struct MeshObject
    {
        public Matrix4x4 localToWorldMatrix;
        public int indices_offset;
        public int indices_count;
        public Vector3 albedo;
        public Vector3 specular;
        public float smoothness;
        public Vector3 emission;
        public float transparency;
        public float refraction;
        public int colormapID;
        public int normalmapID;
        public int metalmapID;
        public int roughmapID;

    }

    struct Sphere
    {
        public Vector3 position;
        public float radius;
        public Vector3 albedo;
        public Vector3 specular;
        public float smoothness;
        public Vector3 emission;
        public float refraction;

    }

    private void Awake()
    {
        _camera = GetComponent<Camera>();

        _transformsToWatch.Add(transform);
        _transformsToWatch.Add(DirectionalLight.transform);
    }

    private void OnEnable()
    {
        _currentSample = 0;
        //RebuildMeshObjectBuffers();

       //    SetUpScene();
    }

    private void OnDisable()
    {
        //_sphereBuffer?.Release();
        _meshObjectBuffer?.Release();
        _vertexBuffer?.Release();
        _indexBuffer?.Release();
        _MUVBuffer?.Release();
    }
    IEnumerator SaveImage() {

        yield return new WaitForEndOfFrame();
        //UnityEngine.ScreenCapture.CaptureScreenshot(Time.time + "-" + _currentSample + ".png");
        int width = Screen.width;
        int height = Screen.height;
        Texture2D tex = new Texture2D(width, height, TextureFormat.RGBAFloat, false);

        // Read screen contents into the texture
        tex.ReadPixels(new Rect(0, 0, width, height), 0, 0);
        tex.Apply();

        // Encode texture into PNG
        byte[] bytes = tex.EncodeToPNG();
        Object.Destroy(tex);

        // For testing purposes, also write to a file in the project folder
        File.WriteAllBytes(Time.time + "-" + _currentSample + ".png", bytes);
    }

    void SaveBitmap()
    {
        var tex = new Texture2D(Screen.width, Screen.height, TextureFormat.RGBA32, false);
        int width = Screen.width;
        int height = Screen.height;

        // Read screen contents into the texture
        tex.ReadPixels(new Rect(0, 0, width, height), 0, 0);
        tex.Apply();
        File.WriteAllBytes(Time.time + "-" + _currentSample + ".png", ImageConversion.EncodeToPNG(tex));
        Destroy(tex);
    }

    private void Update()
    {
        if (shouldRender)
        {
            if (_currentSample == 0)
            {
                bufferCapture.BeginRecording();
            }
            else if (_currentSample == 1)
            {
                bufferCapture.EndRecording();
                bufferCapture.enabled = false;
            }
            if (_currentSample % 50 == 0)
            {
                string name = Time.time + "-" + _currentSample + ".png";

                UnityEngine.ScreenCapture.CaptureScreenshot(name);

                oldname = name;
                //  bufferCapture.BeginRecording();
                //StartCoroutine(SaveImage());
                //byte[] bytes = toTexture2D(_converged).EncodeToPNG();
                //System.IO.File.WriteAllBytes(Time.time + "-" + _currentSample + ".png", bytes);
                //Debug.Log("Saved at sample : " + _currentSample);
            }
            else if (_currentSample % 51 == 0)
            {
                Denoise(Application.dataPath + "/../" + oldname, Application.dataPath + "/../"+"/Capture/");
                //print("Should Denoise : " + Application.dataPath + "/../" + oldname);
                // StartCoroutine(SaveImage());
                // UnityEngine.ScreenCapture.CaptureScreenshot(Time.time + "-" + _currentSample + ".png");

            }
            else
            {
                // bufferCapture.EndRecording();

            }
        }

       

        if (_camera.fieldOfView != _lastFieldOfView)
        {
            _currentSample = 0;
            _lastFieldOfView = _camera.fieldOfView;
        }

        foreach (Transform t in _transformsToWatch)
        {
            if (t.hasChanged)
            {
                _currentSample = 0;
                t.hasChanged = false;
            }
        }
    }

    public static void RegisterObject(RayTracingObject obj)
    {
        _rayTracingObjects.Add(obj);
        _meshObjectsNeedRebuilding = true;
    }
    public static void UnregisterObject(RayTracingObject obj)
    {
        _rayTracingObjects.Remove(obj);
        _meshObjectsNeedRebuilding = true;
    }


    private void RebuildMeshObjectBuffers()
    {
        if (!_meshObjectsNeedRebuilding)
        {
            return;
        }

        _meshObjectsNeedRebuilding = false;
        _currentSample = 0;
        List<Texture2D> colorMaps = new List<Texture2D>();
        List<Texture2D> normalMaps = new List<Texture2D>();
        List<Texture2D> metalMaps = new List<Texture2D>();
        List<Texture2D> roughMaps = new List<Texture2D>();
        // Clear all lists
        _meshObjects.Clear();
        _vertices.Clear();
        _indices.Clear();
        int colormapid=0;
        int normalmapid=0;
        int metalmapid=0;
        int roughmapid=0;
        // Loop over all objects and gather their data
        foreach (RayTracingObject obj in _rayTracingObjects)
        {
            bool hasColorMap = false;
            bool hasNormalMap = false;
            bool hasMetalMap = false;
            bool hasRoughMap = false;
            Mesh mesh = obj.GetComponent<MeshFilter>().sharedMesh;
            Material mat = obj.GetComponent<MeshRenderer>().sharedMaterial;
            if (mat.GetTexture("_MainTex")!=null) {
                colormapid++;
                colorMaps.Add(mat.GetTexture("_MainTex") as Texture2D);
                hasColorMap = true;
            }
            if (mat.GetTexture("_BumpMap")!=null)
            {
                normalmapid++;
                normalMaps.Add(mat.GetTexture("_BumpMap") as Texture2D);
                hasNormalMap = true;

            }
            if (mat.GetTexture("_SpecGlossMap")!=null)
            {
                metalmapid++;
                metalMaps.Add(mat.GetTexture("_SpecGlossMap") as Texture2D);
                hasMetalMap = true;

            }
            if (mat.GetTexture("_SpecGlossMap") !=null)
            {
                //   roughmapid++;
                //   roughMaps.Add(mat.GetTexture("_SpecularGlossMap") as Texture2D);
                //hasRoughMap = true;

            }
            // Add vertex data
            int firstVertex = _vertices.Count;
            _vertices.AddRange(mesh.vertices);

            // Add index data - if the vertex buffer wasn't empty before, the
            // indices need to be offset
            int firstIndex = _indices.Count;
            var indices = mesh.GetIndices(0);
            _indices.AddRange(indices.Select(index => index + firstVertex));
            for (int i = 0; i < _vertices.Count; i++)
            {
                _M_UVs.Add(new Vector2(_vertices[i].x, _vertices[i].z));
            }
            // Add the object itself
            _meshObjects.Add(new MeshObject()
            {
                localToWorldMatrix = obj.transform.localToWorldMatrix,
                indices_offset = firstIndex,
                indices_count = indices.Length,
                albedo = new Vector3(mat.GetColor("_Color").r, mat.GetColor("_Color").g, mat.GetColor("_Color").b),
                specular = new Vector3(mat.GetColor("_SpecColor").r, mat.GetColor("_SpecColor").g, mat.GetColor("_SpecColor").b),
                smoothness = mat.GetFloat("_Glossiness"),
                emission = new Vector3(mat.GetColor("_EmissionColor").r, mat.GetColor("_EmissionColor").g, mat.GetColor("_EmissionColor").b),
                transparency = mat.GetColor("_Color").a,
                refraction = obj.IOR,
                colormapID = colormapid, 
                normalmapID = normalmapid,
                metalmapID = metalmapid,
                roughmapID = roughmapid

            });

        }

        if (colorMaps.Count > 0) {
            Texture2DArray colorMapArray = new Texture2DArray(colorMaps[0].width, colorMaps[0].height, colorMaps.Count, TextureFormat.RGBA32, true, false);
            colorMapArray.filterMode = FilterMode.Bilinear;
            colorMapArray.wrapMode = TextureWrapMode.Repeat;
            // Loop through ordinary textures and copy pixels to the
            // Texture2DArray
            for (int i = 0; i < colorMaps.Count; i++)
            {
                colorMapArray.SetPixels(colorMaps[i].GetPixels(0),
                    i, 0);
            }
            // Apply our changes
            colorMapArray.Apply();
            // Set the texture to a material
            RayTracingShader.SetTexture(0,"colormap", colorMapArray);
        }
        if (normalMaps.Count > 0)
        {
            Texture2DArray normalMapArray = new Texture2DArray(normalMaps[0].width, normalMaps[0].height, normalMaps.Count, TextureFormat.RGBA32, true, false);
            normalMapArray.filterMode = FilterMode.Bilinear;
            normalMapArray.wrapMode = TextureWrapMode.Repeat;
            // Loop through ordinary textures and copy pixels to the
            // Texture2DArray
            for (int i = 0; i < normalMaps.Count; i++)
            {
                normalMapArray.SetPixels(normalMaps[i].GetPixels(0),
                    i, 0);
            }
            // Apply our changes
            normalMapArray.Apply();
            // Set the texture to a material
            RayTracingShader.SetTexture(0, "normalmap", normalMapArray);
        }
        if (metalMaps.Count > 0)
        {
            Texture2DArray metalMapArray = new Texture2DArray(metalMaps[0].width, metalMaps[0].height, metalMaps.Count, TextureFormat.RGBA32, true, false);
            metalMapArray.filterMode = FilterMode.Bilinear;
            metalMapArray.wrapMode = TextureWrapMode.Repeat;
            // Loop through ordinary textures and copy pixels to the
            // Texture2DArray
            for (int i = 0; i < metalMaps.Count; i++)
            {
                metalMapArray.SetPixels(metalMaps[i].GetPixels(0),
                    i, 0);
            }
            // Apply our changes
            metalMapArray.Apply();
            // Set the texture to a material
            RayTracingShader.SetTexture(0, "metalmap", metalMapArray);
        }
        if (roughMaps.Count > 0)
        {
            Texture2DArray roughMapArray = new Texture2DArray(roughMaps[0].width, roughMaps[0].height, roughMaps.Count, TextureFormat.RGBA32, true, false);
            roughMapArray.filterMode = FilterMode.Bilinear;
            roughMapArray.wrapMode = TextureWrapMode.Repeat;
            // Loop through ordinary textures and copy pixels to the
            // Texture2DArray
            for (int i = 0; i < roughMaps.Count; i++)
            {
                roughMapArray.SetPixels(roughMaps[i].GetPixels(0),
                    i, 0);
            }
            // Apply our changes
            roughMapArray.Apply();
            // Set the texture to a material
            RayTracingShader.SetTexture(0, "roughmap", roughMapArray);
        }




        CreateComputeBuffer(ref _meshObjectBuffer, _meshObjects, 136);
        CreateComputeBuffer(ref _vertexBuffer, _vertices, 12);
        CreateComputeBuffer(ref _indexBuffer, _indices, 4);
        CreateComputeBuffer(ref _MUVBuffer, _M_UVs, 8);
    }

    private static void CreateComputeBuffer<T>(ref ComputeBuffer buffer, List<T> data, int stride)
        where T : struct
    {
        // Do we already have a compute buffer?
        if (buffer != null)
        {
            // If no data or buffer doesn't match the given criteria, release it
            if (data.Count == 0 || buffer.count != data.Count || buffer.stride != stride)
            {
                buffer.Release();
                buffer = null;
            }
        }

        if (data.Count != 0)
        {
            // If the buffer has been released or wasn't there to
            // begin with, create it
            if (buffer == null)
            {
                buffer = new ComputeBuffer(data.Count, stride);
            }

            // Set data on the buffer
            buffer.SetData(data);
        }
    }

    private void SetComputeBuffer(string name, ComputeBuffer buffer)
    {
        if (buffer != null)
        {
            RayTracingShader.SetBuffer(0, name, buffer);
        }
    }
    public Texture testTexture;
    private void SetShaderParameters()
    {
        RayTracingShader.SetTexture(0, "_SkyboxTexture", SkyboxTexture);
        RayTracingShader.SetTexture(0, "_NoiseTex1", noiseTex1);
        RayTracingShader.SetTexture(0, "_NoiseTex2", noiseTex2);
        RayTracingShader.SetMatrix("_CameraToWorld", _camera.cameraToWorldMatrix);
        RayTracingShader.SetMatrix("_CameraInverseProjection", _camera.projectionMatrix.inverse);
        RayTracingShader.SetVector("_PixelOffset", new Vector2(Random.value, Random.value));
        RayTracingShader.SetFloat("_Seed", Random.value);
        //RayTracingShader.SetVector("skyColor", new Vector3(skyColor.r , skyColor.g , skyColor.b ));
        RayTracingShader.SetVector("_GroundColor", new Vector3(groundColor.r , groundColor.g , groundColor.b ));
        RayTracingShader.SetVector("sunColor", new Vector3(DirectionalLight.color.r , DirectionalLight.color.g , DirectionalLight.color.b ));
        RayTracingShader.SetVector("_SkyTint", new Vector3(skyTint.r, skyTint.g, skyTint.b));
        RayTracingShader.SetVector("_BackgroundColor", new Vector3(backgroundColor.r, backgroundColor.g, backgroundColor.b));
        RayTracingShader.SetInt("_SkyMode", (int)theSkyMode);
        Vector3 l = DirectionalLight.transform.forward;
        RayTracingShader.SetVector("_DirectionalLight", new Vector4(l.x, l.y, l.z, DirectionalLight.intensity));
        RayTracingShader.SetTexture(0,"_testTexture", testTexture);
        //SetComputeBuffer("_Spheres", _sphereBuffer);
        SetComputeBuffer("_MeshObjects", _meshObjectBuffer);
        SetComputeBuffer("_Vertices", _vertexBuffer);
        SetComputeBuffer("_Indices", _indexBuffer);
        SetComputeBuffer("_M_UVs", _MUVBuffer);
    }

    private void InitRenderTexture()
    {
        if (_target == null || _target.width != Screen.width/ qualityDivider || _target.height != Screen.height/ qualityDivider)
        {
            // Release render texture if we already have one
            if (_target != null)
            {
                _target.Release();
                _converged.Release();
            }

            // Get a render target for Ray Tracing
            _target = new RenderTexture(Screen.width/ qualityDivider, Screen.height/ qualityDivider, 0,
                RenderTextureFormat.ARGBFloat, RenderTextureReadWrite.Linear);
            _target.enableRandomWrite = true;
            _target.Create();
            _converged = new RenderTexture(Screen.width/ qualityDivider, Screen.height/ qualityDivider, 0,
                RenderTextureFormat.ARGBFloat, RenderTextureReadWrite.Linear);
            _converged.enableRandomWrite = true;
            _converged.Create();

            // Reset sampling
            _currentSample = 0;
        }
    }
    public bool shouldRenderRays = false;
    private void Render(RenderTexture destination)
    {

            // Make sure we have a current render target
            InitRenderTexture();

            // Set the target and dispatch the compute shader
            RayTracingShader.SetTexture(0, "Result", _target);
            int threadGroupsX = Mathf.CeilToInt(Screen.width / qualityDivider / 8.0f);
            int threadGroupsY = Mathf.CeilToInt(Screen.height / qualityDivider / 8.0f);
            RayTracingShader.Dispatch(0, threadGroupsX, threadGroupsY, 1);
            // Blit the result texture to the screen
            if (_addMaterial == null)
                _addMaterial = new Material(Shader.Find("Hidden/AddShader"));
            _addMaterial.SetFloat("_Sample", _currentSample);
            Graphics.Blit(_target, _converged, _addMaterial);
            Graphics.Blit(_converged, destination);


        _currentSample++;

        sampleCount.text = _currentSample + " Samples";
        

    }


    public void Denoise(string pathToDenoise, string captureFolder) {
        try
        {
            Process myProcess = new Process();
            myProcess.StartInfo.WindowStyle = ProcessWindowStyle.Normal;
            myProcess.StartInfo.CreateNoWindow = true;
            myProcess.StartInfo.UseShellExecute = false;
            myProcess.StartInfo.FileName = Application.streamingAssetsPath + "\\Denoiser_v2.2\\Denoiser.exe";
            string ipath = "-i " + pathToDenoise;
            string opath = " -o " + pathToDenoise + "_output.png";
            string apath = " -a " + captureFolder + "/Albedo_0000.png";
            string npath = " -n " + captureFolder + "/Normal_0000.png";
            //print("ipath :" + ipath);
            //print(ipath + opath);

            myProcess.StartInfo.Arguments = ipath+opath;
            myProcess.EnableRaisingEvents = true;
            myProcess.Start();
            
            //myProcess.WaitForExit();
            //int ExitCode = myProcess.ExitCode;
            //print(ExitCode);
        }
        catch (System.Exception e)
        {
            print(e);
        }

    }

    Texture2D toTexture2D(RenderTexture rTex)
    {
        Texture2D tex = new Texture2D(rTex.width, rTex.height, TextureFormat.RGBA32, false);
        RenderTexture.active = rTex;
        tex.ReadPixels(new Rect(0, 0, rTex.width, rTex.height), 0, 0);
        tex.Apply();
        return tex;
    }
    private void OnRenderImage(RenderTexture source, RenderTexture destination)
    {
        raySpeed.StartLoop();
        if (shouldRenderRays)
        {
            RebuildMeshObjectBuffers();
            SetShaderParameters();
            Render(destination);

        }
        else {
            Graphics.Blit(source, destination);

        }
        raySpeed.EndLoop((Screen.width / qualityDivider) * (Screen.height / qualityDivider) * 8);
        //raySpeed.UpdateRays((Screen.width / qualityDivider) * (Screen.height / qualityDivider) * 8);
    }
}


___________________________________________________________________________________________________________________
_________________________________________SHADER____________________________________________________________________
#pragma kernel CSMain
#include "UnityCG.cginc"
#include "Lighting.cginc"
RWTexture2D<float4> Result;

float4x4 _CameraToWorld;
float4x4 _CameraInverseProjection;

float4 _DirectionalLight;

float2 _PixelOffset;

Texture2D<float4> _SkyboxTexture;
SamplerState sampler_SkyboxTexture;

static const float PI = 3.14159265f;
static const float EPSILON = 1e-8;
int _SkyMode;
float3 _BackgroundColor;
//-------------------------------------
//- UTILITY

float sdot(float3 x, float3 y, float f = 1.0f)
{
    return saturate(dot(x, y) * f);
}

float energy(float3 color)
{
    return dot(color, 1.0f / 3.0f);
}

//-------------------------------------
//- RANDOMNESS

float2 _Pixel;
float _Seed;
float rand()
{
	//return 0.5;
    float result = frac(sin(_Seed / 100.0f * dot(_Pixel, float2(12.9898f, 78.233f))) * 43758.5453f);
    _Seed += 1.0f;
    return result;
}


//-------------------------------------
//- SPHERES
//
//struct Sphere
//{
//    float3 position;
//    float radius;
//    float3 albedo;
//    float3 specular;
//    float smoothness;
//    float3 emission;
//};

//StructuredBuffer<Sphere> _Spheres;
Texture2DArray<float4> colormap;
Texture2DArray<float4> normalmap;
Texture2DArray<float4> metalmap;
Texture2DArray<float4> roughmap;
SamplerState sampledMap;
//-------------------------------------
//- MESHES

struct MeshObject
{
	float4x4 localToWorldMatrix;
	int indices_offset;
	int indices_count;
	float3 albedo;
	float3 specular;
	float smoothness;
	float3 emission;
	float transparency;
	float refraction;
	int colormapid;
	int normalmapid;
	int metalmapid;
	int roughmapid;

};
Texture2D<float4>    _testTexture;
StructuredBuffer<MeshObject> _MeshObjects;
StructuredBuffer<float3> _Vertices;
StructuredBuffer<int> _Indices;
StructuredBuffer<float2> _M_UVs;


//-------------------------------------
//- RAY

struct Ray
{
    float3 origin;
    float3 direction;
    float3 energy;
	float2 uv;
};

Ray CreateRay(float3 origin, float3 direction, float2 uv)
{
    Ray ray;
    ray.origin = origin;
    ray.direction = direction;
    ray.energy = float3(1.0f, 1.0f, 1.0f);
	ray.uv = uv;
    return ray;
}

Ray CreateCameraRay(float2 uv)
{
    // Transform the camera origin to world space
    float3 origin = mul(_CameraToWorld, float4(0.0f, 0.0f, 0.0f, 1.0f)).xyz;
    
    // Invert the perspective projection of the view-space position
    float3 direction = mul(_CameraInverseProjection, float4(uv, 0.0f, 1.0f)).xyz;
    // Transform the direction from camera to world space and normalize
    direction = mul(_CameraToWorld, float4(direction, 0.0f)).xyz;
    direction = normalize(direction);

    return CreateRay(origin, direction,uv);
}


//-------------------------------------
//- RAYHIT

struct RayHit
{
    float3 position;
    float distance;
    float3 normal;
    float3 albedo;
    float3 specular;
    float smoothness;
    float3 emission;
	float transparency;
	float refraction;
	int colormapid;
	int normalmapid;
	int metalmapid;
	int roughmapid;
	float2 texcoords;
};

RayHit CreateRayHit()
{
    RayHit hit;
    hit.position = float3(0.0f, 0.0f, 0.0f);
    hit.distance = 1.#INF;
    hit.normal = float3(0.0f, 0.0f, 0.0f);
    hit.albedo = float3(0.0f, 0.0f, 0.0f);
    hit.specular = float3(0.0f, 0.0f, 0.0f);
    hit.smoothness = 0.0f;
    hit.emission = float3(0.0f, 0.0f, 0.0f);
    return hit;
}



bool Refract(float3 v, float3 n, float niOverNt, out float3 refracted) {
	float3 uv = normalize(v);
	float dt = dot(uv, n);
	float discriminant = 1.0 - niOverNt * niOverNt * (1 - dt * dt);
	if (discriminant > 0) {
		refracted = niOverNt * (v - n * dt) - n * sqrt(discriminant);
		return true;
	}
	return false;
}

float Schlick(float cosine, float refIdx) {
	float r0 = (1 - refIdx) / (1 + refIdx);
	r0 = r0 * r0;
	return r0 + (1 - r0) * pow((1 - cosine), 5);
}




//-------------------------------------
//- INTERSECTION
//
//void IntersectGroundPlane(Ray ray, inout RayHit bestHit)
//{
//     Calculate distance along the ray where the ground plane is intersected
//    float t = -ray.origin.y / ray.direction.y;
//    if (t > 0 && t < bestHit.distance)
//    {
//        bestHit.distance = t;
//        bestHit.position = ray.origin + t * ray.direction;
//        bestHit.normal = float3(0.0f, 1.0f, 0.0f);
//        bestHit.albedo = 0.5f;
//        bestHit.specular = 1.0f;
//        bestHit.smoothness = 1.0f;
//		bestHit.emission = float3(0.0f, 0.0f, 0.0f);
//		bestHit.transparency = 1.0;
//		bestHit.refraction = 1.0;
//
//    }
//}

//void IntersectSphere(Ray ray, inout RayHit bestHit, Sphere sphere)
//{
//    // Calculate distance along the ray where the sphere is intersected
//    float3 d = ray.origin - sphere.position;
//    float p1 = -dot(ray.direction, d);
//    float p2sqr = p1 * p1 - dot(d, d) + sphere.radius * sphere.radius;
//    if (p2sqr < 0)
//        return;
//    float p2 = sqrt(p2sqr);
//    float t = p1 - p2 > 0 ? p1 - p2 : p1 + p2;
//    if (t > 0 && t < bestHit.distance)
//    {
//        bestHit.distance = t;
//        bestHit.position = ray.origin + t * ray.direction;
//        bestHit.normal = normalize(bestHit.position - sphere.position);
//        bestHit.albedo = sphere.albedo;
//        bestHit.specular = sphere.specular;
//        bestHit.smoothness = sphere.smoothness;
//        bestHit.emission = sphere.emission;
//    }
//}

bool IntersectTriangle_MT97(Ray ray, float3 vert0, float3 vert1, float3 vert2,
	inout float t, inout float u, inout float v)
{
	// find vectors for two edges sharing vert0
	float3 edge1 = vert1 - vert0;
	float3 edge2 = vert2 - vert0;

	// begin calculating determinant - also used to calculate U parameter
	float3 pvec = cross(ray.direction, edge2);

	// if determinant is near zero, ray lies in plane of triangle
	float det = dot(edge1, pvec);

	// use backface culling
	if (det < EPSILON)
		return false;
	float inv_det = 1.0f / det;

	// calculate distance from vert0 to ray origin
	float3 tvec = ray.origin - vert0;

	// calculate U parameter and test bounds
	u = dot(tvec, pvec) * inv_det;
	if (u < 0.0 || u > 1.0f)
		return false;

	// prepare to test V parameter
	float3 qvec = cross(tvec, edge1);

	// calculate V parameter and test bounds
	v = dot(ray.direction, qvec) * inv_det;
	if (v < 0.0 || u + v > 1.0f)
		return false;

	// calculate t, ray intersects triangle
	t = dot(edge2, qvec) * inv_det;

	return true;
}

//float4 _Time;

float _Seed01;

float GradNoise(float2 xy) {
	return frac(52.9829189f * frac(0.06711056f*float(xy.x) + 0.00583715f*float(xy.y)));
}
float Noise(float2 uv) {
	return GradNoise(floor(fmod(uv, 1024)) + _Seed01 * _Time.y);
}

void IntersectMeshObject(Ray ray, inout RayHit bestHit, MeshObject meshObject)
{
	uint offset = meshObject.indices_offset;
	uint count = offset + meshObject.indices_count;
	for (uint i = offset; i < count; i += 3)
	{
		float3 v0 = (mul(meshObject.localToWorldMatrix, float4(_Vertices[_Indices[i]], 1))).xyz;
		float3 v1 = (mul(meshObject.localToWorldMatrix, float4(_Vertices[_Indices[i + 1]], 1))).xyz;
		float3 v2 = (mul(meshObject.localToWorldMatrix, float4(_Vertices[_Indices[i + 2]], 1))).xyz;

		float t, u, v;


		if (IntersectTriangle_MT97(ray, v0, v1, v2, t, u, v))
		{
			if (t > 0 && t < bestHit.distance)
			{
				bestHit.texcoords = float2(u*_M_UVs[_Indices[i + 2]].x, v*_M_UVs[_Indices[i + 2]].y)*1024;
				bestHit.distance = t;
				bestHit.position = ray.origin + t * ray.direction;
				bestHit.normal = normalize(cross(v1 - v0, v2 - v0));
				bestHit.albedo = /*meshObject.albedo **/ colormap[float3(bestHit.texcoords, meshObject.colormapid-1)];  /* / _testTexture[float2(u, v)].xyz*/;
				bestHit.specular = meshObject.specular;
				bestHit.smoothness = meshObject.smoothness;
				bestHit.emission = meshObject.emission;
				bestHit.transparency = meshObject.transparency;
				bestHit.refraction = meshObject.refraction;
				bestHit.colormapid= meshObject.colormapid;
				bestHit.normalmapid = meshObject.normalmapid;
				bestHit.metalmapid = meshObject.metalmapid;
				bestHit.roughmapid = meshObject.roughmapid;


				
			}
		}
	}
}

//-------------------------------------
//- TRACE

RayHit Trace(Ray ray)
{
	RayHit bestHit = CreateRayHit();
	uint count, stride, i;

	// Trace ground plane
	// IntersectGroundPlane(ray, bestHit);

	// Trace spheres
	//_Spheres.GetDimensions(count, stride);
	/*for (i = 0; i < count; i++)
	{
		IntersectSphere(ray, bestHit, _Spheres[i]);
	}
*/
	 //Trace mesh objects
	_MeshObjects.GetDimensions(count, stride);
	if (count > 0) {
		for (i = 0; i < count; i++)
		{
			IntersectMeshObject(ray, bestHit, _MeshObjects[i]);
		}
	}
	 
	return bestHit;
}


//-------------------------------------
//- SKY

half _Exposure;
float3 _GroundColor;
half _SunSize;
float3 _SkyTint;
half _AtmosphereThickness;


#define GAMMA 2.2
#define COLOR_2_GAMMA(color) ((unity_ColorSpaceDouble.r>2.0) ? pow(color,1.0/GAMMA) : color)
#define COLOR_2_LINEAR(color) color
#define LINEAR_2_LINEAR(color) color

// RGB wavelengths
// .35 (.62=158), .43 (.68=174), .525 (.75=190)
static const float3 kDefaultScatteringWavelength = float3(.65, .57, .475);
static const float3 kVariableRangeForScatteringWavelength = float3(.15, .15, .15);

#define OUTER_RADIUS 1.025
static const float kOuterRadius = OUTER_RADIUS;
static const float kOuterRadius2 = OUTER_RADIUS * OUTER_RADIUS;
static const float kInnerRadius = 1.0;
static const float kInnerRadius2 = 1.0;

static const float kCameraHeight = 0.0001;

#define kRAYLEIGH (lerp(0, 0.0025, pow(_AtmosphereThickness,2.5)))		// Rayleigh constant
#define kMIE 0.0010      		// Mie constant
#define kSUN_BRIGHTNESS 20 	// Sun brightness

#define kMAX_SCATTER 50.0 // Maximum scattering value, to prevent math overflows on Adrenos

static const half kSunScale = 400.0 * kSUN_BRIGHTNESS;
static const float kKmESun = kMIE * kSUN_BRIGHTNESS;
static const float kKm4PI = kMIE * 4.0 * 3.14159265;
static const float kScale = 1.0 / (OUTER_RADIUS - 1.0);
static const float kScaleDepth = 0.25;
static const float kScaleOverScaleDepth = (1.0 / (OUTER_RADIUS - 1.0)) / 0.25;
static const float kSamples = 4.0; // THIS IS UNROLLED MANUALLY, DON'T TOUCH

#define MIE_G (-0.990)
#define MIE_G2 0.9801

#define SKY_GROUND_THRESHOLD 0.02


float3 skyColor;
float3 groundColor;
float3 sunColor;


half getRayleighPhase(half eyeCos2)
{
	return 0.75 + 0.75*eyeCos2;
}
half getRayleighPhase(half3 light, half3 ray)
{
	half eyeCos = dot(light, ray);
	return getRayleighPhase(eyeCos * eyeCos);
}


float scale(float inCos)
{
	float x = 1.0 - inCos;
	return 0.25 * exp(-0.00287 + x * (0.459 + x * (3.83 + x * (-6.80 + x * 5.25))));
}
//Thanks Keijiro
void MieSky(Ray r, float2 uv, out float3 skyColor, inout float3 groundColor, inout float3 sunColor) {
	_Exposure = 1.45;
	_AtmosphereThickness = 1;

	float3 kSkyTintInGammaSpace = COLOR_2_GAMMA(_SkyTint); // convert tint from Linear back to Gamma
	float3 kScatteringWavelength = lerp(
		kDefaultScatteringWavelength - kVariableRangeForScatteringWavelength,
		kDefaultScatteringWavelength + kVariableRangeForScatteringWavelength,
		half3(1, 1, 1) - kSkyTintInGammaSpace); // using Tint in sRGB gamma allows for more visually linear interpolation and to keep (.5) at (128, gray in sRGB) point
	float3 kInvWavelength = 1.0 / pow(kScatteringWavelength, 4);

	float kKrESun = kRAYLEIGH * kSUN_BRIGHTNESS;
	float kKr4PI = kRAYLEIGH * 4.0 * 3.14159265;

	float3 cameraPos = float3(0, kInnerRadius + kCameraHeight, 0); 	// The camera's current position

	// Get the ray from the camera to the vertex and its length (which is the far point of the ray passing through the atmosphere)
	float3 eyeRay = r.direction;

	float far = 0.0;
	half3 cIn, cOut;

	if (eyeRay.y >= 0.0)
	{
		// Sky
		// Calculate the length of the "atmosphere"
		far = sqrt(kOuterRadius2 + kInnerRadius2 * eyeRay.y * eyeRay.y - kInnerRadius2) - kInnerRadius * eyeRay.y;

		float3 pos = cameraPos + far * eyeRay;

		// Calculate the ray's starting position, then calculate its scattering offset
		float height = kInnerRadius + kCameraHeight;
		float depth = exp(kScaleOverScaleDepth * (-kCameraHeight));
		float startAngle = dot(eyeRay, cameraPos) / height;
		float startOffset = depth * scale(startAngle);


		// Initialize the scattering loop variables
		float sampleLength = far / kSamples;
		float scaledLength = sampleLength * kScale;
		float3 sampleRay = eyeRay * sampleLength;
		float3 samplePoint = cameraPos + sampleRay * 0.5;

		// Now loop through the sample rays
		float3 frontColor = float3(0.0, 0.0, 0.0);
		// Weird workaround: WP8 and desktop FL_9_1 do not like the for loop here
		// (but an almost identical loop is perfectly fine in the ground calculations below)
		// Just unrolling this manually seems to make everything fine again.
		for(int i=0; i<int(kSamples); i++)
		{
			float height = length(samplePoint);
			float depth = exp(kScaleOverScaleDepth * (kInnerRadius - height));
			float lightAngle = dot(_WorldSpaceLightPos0.xyz, samplePoint) / height;
			float cameraAngle = dot(eyeRay, samplePoint) / height;
			float scatter = (startOffset + depth * (scale(lightAngle) - scale(cameraAngle)));
			float3 attenuate = exp(-clamp(scatter, 0.0, kMAX_SCATTER) * (kInvWavelength * kKr4PI + kKm4PI));

			frontColor += attenuate * (depth * scaledLength);
			samplePoint += sampleRay;
		}

		// Finally, scale the Mie and Rayleigh colors and set up the varying variables for the pixel shader
		cIn = frontColor * (kInvWavelength * kKrESun);
		cOut = frontColor * kKmESun;
	}
	else
	{
		// Ground
		far = (-kCameraHeight) / (min(-0.001, eyeRay.y));

		float3 pos = cameraPos + far * eyeRay;

		// Calculate the ray's starting position, then calculate its scattering offset
		float depth = exp((-kCameraHeight) * (1.0 / kScaleDepth));
		float cameraAngle = dot(-eyeRay, pos);
		float lightAngle = dot(_WorldSpaceLightPos0.xyz, pos);
		float cameraScale = scale(cameraAngle);
		float lightScale = scale(lightAngle);
		float cameraOffset = depth * cameraScale;
		float temp = (lightScale + cameraScale);

		// Initialize the scattering loop variables
		float sampleLength = far / kSamples;
		float scaledLength = sampleLength * kScale;
		float3 sampleRay = eyeRay * sampleLength;
		float3 samplePoint = cameraPos + sampleRay * 0.5;

		// Now loop through the sample rays
		float3 frontColor = float3(0.0, 0.0, 0.0);
		float3 attenuate;
		for(int i=0; i<int(kSamples); i++) // Loop removed because we kept hitting SM2.0 temp variable limits. Doesn't affect the image too much.
		{
			float height = length(samplePoint);
			float depth = exp(kScaleOverScaleDepth * (kInnerRadius - height));
			float scatter = depth * temp - cameraOffset;
			attenuate = exp(-clamp(scatter, 0.0, kMAX_SCATTER) * (kInvWavelength * kKr4PI + kKm4PI));
			frontColor += attenuate * (depth * scaledLength);
			samplePoint += sampleRay;
		}

		cIn = frontColor * (kInvWavelength * kKrESun + kKmESun);
		cOut = clamp(attenuate, 0.0, 1.0);
	}

	groundColor = _Exposure * (cIn + COLOR_2_LINEAR(_GroundColor) * cOut);
	skyColor = _Exposure * (cIn * getRayleighPhase(_WorldSpaceLightPos0.xyz, -eyeRay));
	sunColor = _Exposure * (cOut * _LightColor0.xyz);
}




half calcSunSpot(half3 vec1, half3 vec2)
{
	half3 delta = vec1 - vec2;
	half dist = length(delta);
	half spot = 1.0 - smoothstep(0.0, 0.03, dist);
	return kSunScale * spot * spot;
}


float _SampleCount0 =8;
float _SampleCount1 = 64;
int _SampleCountL = 8;

sampler3D _NoiseTex1;
sampler3D _NoiseTex2;
float _NoiseFreq1 = 1.34;
float _NoiseFreq2 = 13.57;
float _NoiseAmp1 = -8.5;
float _NoiseAmp2 = 2.49;
float _NoiseBias = 2.19;

float3 _Scroll1;
float3 _Scroll2;

float _Altitude0 = 1000;
float _Altitude1 = 5000;
float _FarDist = 22000;

float _Scatter =0.009;
float _HGCoeff = 0.4;
float _Extinct = 0.0025;

float UVRandom(float2 uv)
{
	float f = dot(float2(12.9898, 78.233), uv);
	return frac(43758.5453 * sin(f));
}

float SampleNoise(float3 uvw)
{
	const float baseFreq = 1e-5;

	float4 uvw1 = float4(uvw * _NoiseFreq1 * baseFreq, 0);
	float4 uvw2 = float4(uvw * _NoiseFreq2 * baseFreq, 0);

	uvw1.xyz += _Scroll1.xyz * _Time.x;
	uvw2.xyz += _Scroll2.xyz * _Time.x;

	float n1 = tex3Dlod(_NoiseTex1, uvw1).a;
	float n2 = tex3Dlod(_NoiseTex2, uvw2).a;
	float n = n1 * _NoiseAmp1 + n2 * _NoiseAmp2;

	n = saturate(n + _NoiseBias);

	float y = uvw.y - _Altitude0;
	float h = _Altitude1 - _Altitude0;
	n *= smoothstep(0, h * 0.1, y);
	n *= smoothstep(0, h * 0.4, h - y);

	return n;
}

float HenyeyGreenstein(float cosine)
{
	float g2 = _HGCoeff * _HGCoeff;
	return 0.5 * (1 - g2) / pow(1 + g2 - 2 * _HGCoeff * cosine, 1.5);
}

float Beer(float depth)
{
	return exp(-_Extinct * depth);
}

float BeerPowder(float depth)
{
	return exp(-_Extinct * depth) * (1 - exp(-_Extinct * 2 * depth));
}

float MarchLight(float3 pos, float rand)
{
	float3 light = _WorldSpaceLightPos0.xyz;
	float stride = (_Altitude1 - pos.y) / (light.y * _SampleCountL);

	pos += light * stride * rand;

	float depth = 0;
	UNITY_LOOP for (int s = 0; s < _SampleCountL; s++)
	{
		depth += SampleNoise(pos) * stride;
		pos += light * stride;
	}

	return BeerPowder(depth);
}
float4 SkyColor(Ray r, float2 uv) {

	MieSky(r, r.uv, skyColor, groundColor, sunColor);
	//New Method
	half3 col = half3(0.0, 0.0, 0.0);

	// if y > 1 [eyeRay.y < -SKY_GROUND_THRESHOLD] - ground
	// if y >= 0 and < 1 [eyeRay.y <= 0 and > -SKY_GROUND_THRESHOLD] - horizon
	// if y < 0 [eyeRay.y > 0] - sky
	half3 ray = -r.direction;
	half y = ray.y / SKY_GROUND_THRESHOLD;

	//lerp between colors calculated by MieSky
	col = lerp(skyColor, groundColor, saturate(y));

	/*if (y < 0.0)
	{
		half mie = calcSunSpot(_WorldSpaceLightPos0.xyz, -ray);
		col += mie * sunColor;
	}*/

	return half4(col, 1);
}
float3 Clouds(Ray rayIn) {

	 float3 sky = SkyColor(rayIn, rayIn.uv);

	 _SampleCount0 = 64;
	 _SampleCount1 = 128;
	 _SampleCountL = 32;
	 _NoiseFreq1 = 1.34;
	 _NoiseFreq2 = 13.57;
	 _NoiseAmp1 = -8.5;
	 _NoiseAmp2 = 2.49;
	 _NoiseBias = 2.19;

	 //_Scroll1 = float3(0.01,0.08,0.06);
	 //_Scroll2 = float3(0.01, 0.05, 0.03);

	 _Altitude0 = 300;
	 _Altitude1 = 5000;
	 _FarDist = 22000;

	 _Scatter = 0.009;
	 _HGCoeff = 0.4;
	 _Extinct = 0.0025;
	float3 ray = rayIn.direction;
	int samples = lerp(_SampleCount1, _SampleCount0, ray.y);

	float dist0 = _Altitude0 / ray.y;
	float dist1 = _Altitude1 / ray.y;
	float stride = (dist1 - dist0) / samples;
	half3 col = sky;
	half y = -ray.y / SKY_GROUND_THRESHOLD;

	if (y < 0.0)
	{
		half mie = calcSunSpot(_WorldSpaceLightPos0.xyz, ray);
		col += mie * _LightColor0;
	}
	if (ray.y < 0.01 || dist0 >= _FarDist) return fixed4(sky+col, 1);


	float3 light = _WorldSpaceLightPos0.xyz;
	float dotDot = dot(ray, light);

	//float3 viewLightDir = normalize( mul((float3x3)UNITY_MATRIX_V, _WorldSpaceLightPos0.xyz));
	//float3 eyeRay = normalize(mul((float3x3)unity_ObjectToWorld, _WorldSpaceLightPos0.xyz));
	float3 acc = 0;
	float yMult = 0;
	float depth = 0;
	float hg = HenyeyGreenstein(dotDot);

	float2 uv = rayIn.uv + _Time.x;
	float offs = UVRandom(uv) * (dist1 - dist0) / samples;

	float3 pos = _WorldSpaceCameraPos + ray * (dist0 + offs);


	UNITY_LOOP for (int s = 0; s < samples; s++)
	{
		float n = SampleNoise(pos);
		if (n > 0)
		{
			float density = n * stride;
			float rand = UVRandom(uv + s + 1);
			float scatter = ((density * _Scatter * hg)) * MarchLight(pos, rand * 0.5);
			if (light.y > 0)acc += _LightColor0 * scatter * BeerPowder(depth);
			depth += density;

		}
		pos += ray * stride;
	}
	
	col *= Beer(depth);
	float3 sun = float3(0, 0, 0);
	if (col.r >= 1) {
		sun = col;
	}

	acc += Beer(depth) * sky;

	acc = lerp(acc, sky, saturate(dist0 / _FarDist));
	acc += sun;
	return acc;
}


//SimpleColors
float3 EnvColor2(Ray r, float2 uv) {
	float3 unitDirection = (r.direction);
	float t = 0.5 * (unitDirection.y + 1.0);
	return 1.0 * ((1.0 - t) * float3(1.0, 1.0, 1.0) + t * float3(0.5, 0.7, 1.0));
}

//SimpleSun+Colors
float3 EnvColor3(Ray r) {
	half p = r.direction.y;
	half3 ray = r.direction;
	float p1 = pow(min(1.0f, 1.0f - p), 15);
	float p2 = 1.0f - p1;

	// Our moon circle
	half mie = calcSunSpot(_DirectionalLight.xyz, -ray);
	// Blend ground fog with the moon
	half3 col = _GroundColor * p1 + mie * p2;
	// Add sky color
	col += _SkyTint * p2;

	return col;
}



//-------------------------------------
//- SAMPLING

float3x3 GetTangentSpace(float3 normal)
{
    // Choose a helper vector for the cross product
    float3 helper = float3(1, 0, 0);
    if (abs(normal.x) > 0.99f)
        helper = float3(0, 0, 1);

    // Generate vectors
    float3 tangent = normalize(cross(normal, helper));
    float3 binormal = normalize(cross(normal, tangent));
    return float3x3(tangent, binormal, normal);
}

float3 SampleHemisphere(float3 normal, float alpha)
{
    // Sample the hemisphere, where alpha determines the kind of the sampling
    float cosTheta = pow(rand(), 1.0f / (alpha + 1.0f));
    float sinTheta = sqrt(1.0f - cosTheta * cosTheta);
    float phi = 2 * PI * rand();
    float3 tangentSpaceDir = float3(cos(phi) * sinTheta, sin(phi) * sinTheta, cosTheta);

    // Transform direction to world space
    return mul(tangentSpaceDir, GetTangentSpace(normal));
}

//-------------------------------------
//- SHADE

float SmoothnessToPhongAlpha(float s)
{
    return pow(1000.0f, s * s);
}


float3 Shadow(RayHit hit) {

	bool shadow = false;
	Ray shadowRay = CreateRay(hit.position + hit.normal * 0.001f, -1 * _DirectionalLight.xyz, float2(0, 0));
	RayHit shadowHit = Trace(shadowRay);
	if (shadowHit.distance != 1.#INF)
	{
		return float3(0.0f, 0.0f, 0.0f);
	}
	else return _LightColor0.xyz*_DirectionalLight.w;
}


float3 Shade(inout Ray ray, RayHit hit)
{
    if (hit.distance < 1.#INF)
    {
        // Calculate chances of diffuse and specular reflection
        hit.albedo = min(hit.transparency - hit.specular, hit.albedo);
        float specChance = energy(hit.specular);
        float diffChance = energy(hit.albedo);
		float transparencyChance = (hit.transparency);
		float sum = specChance + diffChance;
		//specChance /= sum;
		//diffChance /= sum;


		//float inShadow = _LightColor0.xyz*_DirectionalLight.w;
		//if (shadow.distance != 1.#INF)
		//{
		//	inShadow = float3(0.0f, 0.0f, 0.0f);
		//}

        // Roulette-select the ray's path
        float roulette = rand();
        if (roulette < specChance)
        {
            //// Specular reflection

			//float alpha = 15.0f;
			//ray.origin = hit.position + hit.normal * 0.001f;
			//ray.direction = SampleHemisphere(reflect(ray.direction, hit.normal), alpha);
			//float f = (alpha + 2) / (alpha + 1);
			//ray.energy *= (1.0f / specChance) * hit.specular * sdot(hit.normal, ray.direction, f);

			ray.origin = hit.position + hit.normal * 0.001f;

			float alpha = SmoothnessToPhongAlpha(hit.smoothness);
			if(hit.smoothness ==1)ray.direction = reflect(ray.direction, hit.normal);
			else
            ray.direction = SampleHemisphere(reflect(ray.direction, hit.normal), alpha);
            float f = (alpha + 2) / (alpha + 1);
            ray.energy *= (1.0f / specChance) * hit.specular * sdot(hit.normal, ray.direction, f);

			//float3 specular = float3(0.6f, 0.6f, 0.6f);
			// Reflect the ray and multiply energy with specular reflection
			//ray.origin = hit.position + hit.normal * 0.001f;
			//ray.direction = reflect(ray.direction, hit.normal);
			//ray.energy *= specular;
			// Return nothing
			//return float3(0.0f, 0.0f, 0.0f);

        }

        else if (diffChance > 0 && transparencyChance == 1 && roulette < specChance + diffChance)
        {
            //// Diffuse reflection
            ray.origin = hit.position + hit.normal * 0.001f;
            ray.direction = SampleHemisphere(hit.normal, 1.0f);
            ray.energy *= (1.0f / diffChance) * hit.albedo;
        }

		 else if (transparencyChance < 1) {
			const float refIdx = hit.refraction;

			//1.56 ior reflection;
			float3 outwardNormal;
			float niOverNt;
			float3 refracted;
			float cosine;

			if (dot(ray.direction, hit.normal) > 0) {
				outwardNormal = -hit.normal;
				niOverNt = refIdx;
				cosine = refIdx * dot(ray.direction, hit.normal) / length(ray.direction);
			}
			else {
				outwardNormal = hit.normal;
				niOverNt = 1.0 / refIdx;
				cosine = -dot(ray.direction, hit.normal) / length(ray.direction);
			}

			float reflectProb = lerp(1.0, Schlick(cosine, refIdx),
				Refract(ray.direction, outwardNormal, niOverNt, refracted));

			float alpha = SmoothnessToPhongAlpha(1 - transparencyChance);

			ray.origin = hit.position;
			ray.direction = refracted;

			float f = (alpha + 2) / (alpha + 1);
			ray.energy *= (1.0f / diffChance) * (hit.albedo)*(1-transparencyChance);
		}
        else
        {
            // Terminate ray
            ray.energy = 0.0f;
        }

        return hit.emission;
    }
    else
    {
        // Erase the ray's energy - the sky doesn't reflect anything
        ray.energy = 0.0f;

        // Sample the skybox and write it
        float theta = acos(ray.direction.y) / -PI;
        float phi = atan2(ray.direction.x, -ray.direction.z) / -PI * 0.5f;
		if (_SkyMode == 0)return (float3(_BackgroundColor.x, _BackgroundColor.y, _BackgroundColor.z));
		else if(_SkyMode == 1)return (Clouds(ray));
		else if(_SkyMode ==2)return (_SkyboxTexture.SampleLevel(sampler_SkyboxTexture, float2(phi, theta), 0).xyz);
		else return float3(0, 0, 0);

    }

}


//-------------------------------------
//- KERNEL

[numthreads(8,8,1)]
void CSMain (uint3 id : SV_DispatchThreadID)
{
    _Pixel = id.xy;

    // Get the dimensions of the RenderTexture
    uint width, height;
    Result.GetDimensions(width, height);

    // Transform pixel to [-1,1] range
    float2 uv = float2((id.xy + _PixelOffset) / float2(width, height) * 2.0f - 1.0f);

    // Get a ray for the UVs
    Ray ray = CreateCameraRay(uv);

    // Trace and shade the ray
    float3 result = float3(0, 0, 0);
    for (int i = 0; i < 8; i++)
    {
        RayHit hit = Trace(ray);
		//Ray shadowRay = CreateRay(hit.position + hit.normal * 0.001f, -1 * _DirectionalLight.xyz, float2(0, 0));
		//RayHit shadowHit = Trace(shadowRay);
        result += ray.energy * Shade(ray, hit);
		//result += Shadow(hit);

        if (!any(ray.energy))
            break;
    }

    Result[id.xy] = float4(result, 1);
}

https://chronokun.github.io/posts/2018-05-29--0.html

https://www.ea.com/seed/news/seed-dd18-presentation-slides-raytracing

https://canvas.dartmouth.edu/courses/16840/assignments/82763

https://www.scratchapixel.com/lessons/3d-basic-rendering/ray-tracing-rendering-a-triangle/barycentric-coordinates

https://computergraphics.stackexchange.com/questions/7738/how-to-assign-calculate-triangle-texture-coordinates

http://community.monogame.net/t/raycast-to-texture-coord-or-3d-point-to-texture-coord/10457/5

http://www.cs.yorku.ca/~amana/research/mesh.pdf