js file for experimental sphere BVH (as opposed to typical AABB BVH)

BVH_Point_Light_Source.js

// scene/demo-specific variables go here
let modelMesh;
let modelScale = 1.0;
let modelPositionOffset = new THREE.Vector3();
let albedoTexture;
let total_number_of_triangles = 0;
let triangle_array;
let triangleMaterialMarkers = [];
let pathTracingMaterialList = [];
let uniqueMaterialTextures = [];
let meshList = [];
let geoList = [];
let triangleDataTexture;
let aabb_array;
let aabbDataTexture;
let totalWorklist;
let vp0 = new THREE.Vector3();
let vp1 = new THREE.Vector3();
let vp2 = new THREE.Vector3();
let vn0 = new THREE.Vector3();
let vn1 = new THREE.Vector3();
let vn2 = new THREE.Vector3();
let vt0 = new THREE.Vector2();
let vt1 = new THREE.Vector2();
let vt2 = new THREE.Vector2();


function MaterialObject() 
{
	// a list of material types and their corresponding numbers are found in the 'pathTracingCommon.js' file
	this.type = 1; // default is '1': diffuse type 		
	this.albedoTextureID = -1; // which diffuse map to use for model's color / '-1' = no textures are used
	this.color = new THREE.Color(1.0, 1.0, 1.0); // takes on different meanings, depending on 'type' above
	this.roughness = 0.0; // 0.0 to 1.0 range, perfectly smooth to extremely rough
	this.metalness = 0.0; // 0.0 to 1.0 range, usually either 0 or 1, either non-metal or metal
	this.opacity = 1.0;   // 0.0 to 1.0 range, fully transparent to fully opaque
	this.refractiveIndex = 1.0; // 1.0=air, 1.33=water, 1.4=clearCoat, 1.5=glass, etc.
}


function load_GLTF_Model() 
{

	let gltfLoader = new GLTFLoader();

	gltfLoader.load("models/StanfordBunny.glb", function (meshGroup) // Triangles: 30,338
	//gltfLoader.load("models/UtahTeapot.glb", function( meshGroup ) // Triangles: 992
	//gltfLoader.load("models/TheSentinel_tree.glb", function (meshGroup) // Triangles: 18-60
	//gltfLoader.load("models/StanfordDragon.glb", function (meshGroup) // Triangles: 100,000
	//gltfLoader.load("models/FairyScene.glb", function (meshGroup) // Triangles: 100,000
	{

		if (meshGroup.scene)
			meshGroup = meshGroup.scene;

		meshGroup.traverse(function (child) 
		{

			if (child.isMesh) 
			{
				let mat = new MaterialObject();
				mat.type = 1;
				mat.albedoTextureID = -1;
				mat.color = child.material.color;
				mat.roughness = child.material.roughness || 0.0;
				mat.metalness = child.material.metalness || 0.0;
				mat.opacity = child.material.opacity || 1.0;
				mat.refractiveIndex = 1.0;
				pathTracingMaterialList.push(mat);
				triangleMaterialMarkers.push(child.geometry.attributes.position.array.length / 9);
				meshList.push(child);
			}
		});

		modelMesh = meshList[0].clone();

		for (let i = 0; i < meshList.length; i++) 
		{
			geoList.push(meshList[i].geometry);
		}

		modelMesh.geometry = mergeGeometries(geoList);

		if (modelMesh.geometry.index)
			modelMesh.geometry = modelMesh.geometry.toNonIndexed();

		modelMesh.geometry.center();

		for (let i = 1; i < triangleMaterialMarkers.length; i++) 
		{
			triangleMaterialMarkers[i] += triangleMaterialMarkers[i - 1];
		}


		/* for (let i = 0; i < meshList.length; i++) 
		{
			if (meshList[i].material.map != undefined)
				uniqueMaterialTextures.push(meshList[i].material.map);		
		}
	        
		for (let i = 0; i < uniqueMaterialTextures.length; i++) 
		{
			for (let j = i + 1; j < uniqueMaterialTextures.length; j++) 
			{
				if (uniqueMaterialTextures[i].image.src == uniqueMaterialTextures[j].image.src) 
				{
					uniqueMaterialTextures.splice(j, 1);
					j -= 1;
				}
			}	
		}
	        
		for (let i = 0; i < meshList.length; i++) 
		{
			if (meshList[i].material.map != undefined) 
			{
				for (let j = 0; j < uniqueMaterialTextures.length; j++) 
				{
					if (meshList[i].material.map.image.src == uniqueMaterialTextures[j].image.src) 
					{
						pathTracingMaterialList[i].albedoTextureID = j;
					}
				}
			}				
		} */

		// ********* different GLTF Model Settings **********

		// settings for StanfordBunny model
		modelScale = 0.5;//0.04;
		modelPositionOffset.set(0, 27.6, -40);

		// settings for UtahTeapot model
		// modelScale = 1.0;
		// modelPositionOffset.set(0, 25.6, -40);

		// settings for TheSentinel models
		// modelScale = 20.0;
		// modelPositionOffset.set(0, 30, 0);

		// settings for StanfordDragon model
		// modelScale = 2.0;
		// modelPositionOffset.set(0, 28, -40);

		// settings for various test models
		// modelScale = 6;
		// modelPositionOffset.set(0, 20, 0);

		// now that the model has been loaded, we can init 
		init();

	});

} // end function load_GLTF_Model()



// called automatically from within initTHREEjs() function (located in InitCommon.js file)
function initSceneData() 
{
	demoFragmentShaderFileName = 'BVH_Point_Light_Source_Fragment.glsl';

	// scene/demo-specific three.js objects setup goes here
	sceneIsDynamic = false;
	
	cameraFlightSpeed = 60;

	// pixelRatio is resolution - range: 0.5(half resolution) to 1.0(full resolution)
	pixelRatio = mouseControl ? 0.5 : 0.75; // less demanding on battery-powered mobile devices

	EPS_intersect = 0.001;

	// set camera's field of view
	worldCamera.fov = 60;
	focusDistance = 95.0;
	apertureChangeSpeed = 5;

	// position and orient camera
	cameraControlsObject.position.set(0, 30, 60);
	// look slightly downward
	//cameraControlsPitchObject.rotation.x = -0.2;


	total_number_of_triangles = modelMesh.geometry.attributes.position.array.length / 9;
	console.log("Triangle count:" + total_number_of_triangles);

	totalWorklist = new Uint32Array(total_number_of_triangles);

	triangle_array = new Float32Array(4096 * 4096 * 4);
	// 4096 = width of texture, 4096 = height of texture, 4 = r,g,b, and a components

	aabb_array = new Float32Array(4096 * 4096 * 4);
	// 4096 = width of texture, 4096 = height of texture, 4 = r,g,b, and a components


	let triangle_b_box_min = new THREE.Vector3();
	let triangle_b_box_max = new THREE.Vector3();
	let triangle_centroid = new THREE.Vector3();
	//let triangle_b_box_centroid = new THREE.Vector3();


	let vpa = new Float32Array(modelMesh.geometry.attributes.position.array);
	let vna = new Float32Array(modelMesh.geometry.attributes.normal.array);
	let vta = null;
	let modelHasUVs = false;
	if (modelMesh.geometry.attributes.uv !== undefined) 
	{
		vta = new Float32Array(modelMesh.geometry.attributes.uv.array);
		modelHasUVs = true;
	}

	let materialNumber = 0;

	for (let i = 0; i < total_number_of_triangles; i++) 
	{

		triangle_b_box_min.set(Infinity, Infinity, Infinity);
		triangle_b_box_max.set(-Infinity, -Infinity, -Infinity);

		for (let j = 0; j < pathTracingMaterialList.length; j++) 
		{
			if (i < triangleMaterialMarkers[j]) 
			{
				materialNumber = j;
				break;
			}
		}

		// record vertex texture coordinates (UVs)
		if (modelHasUVs) 
		{
			vt0.set(vta[6 * i + 0], vta[6 * i + 1]);
			vt1.set(vta[6 * i + 2], vta[6 * i + 3]);
			vt2.set(vta[6 * i + 4], vta[6 * i + 5]);
		}
		else 
		{
			vt0.set(-1, -1);
			vt1.set(-1, -1);
			vt2.set(-1, -1);
		}

		// record vertex normals
		vn0.set(vna[9 * i + 0], vna[9 * i + 1], vna[9 * i + 2]).normalize();
		vn1.set(vna[9 * i + 3], vna[9 * i + 4], vna[9 * i + 5]).normalize();
		vn2.set(vna[9 * i + 6], vna[9 * i + 7], vna[9 * i + 8]).normalize();

		// record vertex positions
		vp0.set(vpa[9 * i + 0], vpa[9 * i + 1], vpa[9 * i + 2]);
		vp1.set(vpa[9 * i + 3], vpa[9 * i + 4], vpa[9 * i + 5]);
		vp2.set(vpa[9 * i + 6], vpa[9 * i + 7], vpa[9 * i + 8]);

		vp0.multiplyScalar(modelScale);
		vp1.multiplyScalar(modelScale);
		vp2.multiplyScalar(modelScale);

		vp0.add(modelPositionOffset);
		vp1.add(modelPositionOffset);
		vp2.add(modelPositionOffset);

		//slot 0
		triangle_array[32 * i + 0] = vp0.x; // r or x
		triangle_array[32 * i + 1] = vp0.y; // g or y 
		triangle_array[32 * i + 2] = vp0.z; // b or z
		triangle_array[32 * i + 3] = vp1.x; // a or w

		//slot 1
		triangle_array[32 * i + 4] = vp1.y; // r or x
		triangle_array[32 * i + 5] = vp1.z; // g or y
		triangle_array[32 * i + 6] = vp2.x; // b or z
		triangle_array[32 * i + 7] = vp2.y; // a or w

		//slot 2
		triangle_array[32 * i + 8] = vp2.z; // r or x
		triangle_array[32 * i + 9] = vn0.x; // g or y
		triangle_array[32 * i + 10] = vn0.y; // b or z
		triangle_array[32 * i + 11] = vn0.z; // a or w

		//slot 3
		triangle_array[32 * i + 12] = vn1.x; // r or x
		triangle_array[32 * i + 13] = vn1.y; // g or y
		triangle_array[32 * i + 14] = vn1.z; // b or z
		triangle_array[32 * i + 15] = vn2.x; // a or w

		//slot 4
		triangle_array[32 * i + 16] = vn2.y; // r or x
		triangle_array[32 * i + 17] = vn2.z; // g or y
		triangle_array[32 * i + 18] = vt0.x; // b or z
		triangle_array[32 * i + 19] = vt0.y; // a or w

		//slot 5
		triangle_array[32 * i + 20] = vt1.x; // r or x
		triangle_array[32 * i + 21] = vt1.y; // g or y
		triangle_array[32 * i + 22] = vt2.x; // b or z
		triangle_array[32 * i + 23] = vt2.y; // a or w

		// the remaining slots are used for PBR material properties

		//slot 6
		triangle_array[32 * i + 24] = pathTracingMaterialList[materialNumber].type; // r or x 
		triangle_array[32 * i + 25] = pathTracingMaterialList[materialNumber].color.r; // g or y
		triangle_array[32 * i + 26] = pathTracingMaterialList[materialNumber].color.g; // b or z
		triangle_array[32 * i + 27] = pathTracingMaterialList[materialNumber].color.b; // a or w

		//slot 7
		triangle_array[32 * i + 28] = pathTracingMaterialList[materialNumber].albedoTextureID; // r or x
		triangle_array[32 * i + 29] = 0; // g or y
		triangle_array[32 * i + 30] = 0; // b or z
		triangle_array[32 * i + 31] = 0; // a or w

		triangle_b_box_min.copy(triangle_b_box_min.min(vp0));
		triangle_b_box_max.copy(triangle_b_box_max.max(vp0));
		triangle_b_box_min.copy(triangle_b_box_min.min(vp1));
		triangle_b_box_max.copy(triangle_b_box_max.max(vp1));
		triangle_b_box_min.copy(triangle_b_box_min.min(vp2));
		triangle_b_box_max.copy(triangle_b_box_max.max(vp2));

		//triangle_b_box_centroid.copy(triangle_b_box_min).add(triangle_b_box_max).multiplyScalar(0.5);
		triangle_centroid.copy(vp0).add(vp1).add(vp2).multiplyScalar(0.3333333333333333);

		aabb_array[9 * i + 0] = triangle_b_box_min.x;
		aabb_array[9 * i + 1] = triangle_b_box_min.y;
		aabb_array[9 * i + 2] = triangle_b_box_min.z;
		aabb_array[9 * i + 3] = triangle_b_box_max.x;
		aabb_array[9 * i + 4] = triangle_b_box_max.y;
		aabb_array[9 * i + 5] = triangle_b_box_max.z;
		aabb_array[9 * i + 6] = triangle_centroid.x;
		aabb_array[9 * i + 7] = triangle_centroid.y;
		aabb_array[9 * i + 8] = triangle_centroid.z;

		totalWorklist[i] = i;
	}


	for (let i = 0; i < total_number_of_triangles * 2; i++)
		buildnodes[i] = new BVH_Node();

	console.log("BvhGeneration...");
	console.time("BvhGeneration");
	
	BVH_QuickBuild(totalWorklist, aabb_array);
	
	console.timeEnd("BvhGeneration");

	let box = new THREE.Box3();
	let sphere = new THREE.Sphere();
	let sphereRadiusPacked = 0;
	let leafOrChildID = 0;
	// Copy the buildnodes array into the aabb_array
	for (let n = 0; n < buildnodes.length; n++)
	{
		box.set(buildnodes[n].minCorner, buildnodes[n].maxCorner);
		box.getBoundingSphere(sphere);

		sphereRadiusPacked = sphere.radius * 0.001; // shove radius over into the fractional part of a float number
		leafOrChildID = Math.floor(buildnodes[n].leafOrChild_ID); // keep leftChildID in the integer part of a float number
		
		// this packed bounding volume node now takes only 1 rgba texel!
		if (buildnodes[n].primitiveCount == 0) // inner nodes are encoded as a negative number
			aabb_array[4 * n + 0] = -leafOrChildID - sphereRadiusPacked;  // r or x component
		else 
			aabb_array[4 * n + 0] = leafOrChildID + sphereRadiusPacked;  // r or x component
		aabb_array[4 * n + 1] = sphere.center.x;  // g or y component
		aabb_array[4 * n + 2] = sphere.center.y;  // b or z component
		aabb_array[4 * n + 3] = sphere.center.z;  // a or w component
	}


	triangleDataTexture = new THREE.DataTexture(triangle_array,
		4096,
		4096,
		THREE.RGBAFormat,
		THREE.FloatType,
		THREE.Texture.DEFAULT_MAPPING,
		THREE.ClampToEdgeWrapping,
		THREE.ClampToEdgeWrapping,
		THREE.NearestFilter,
		THREE.NearestFilter,
		1,
		THREE.NoColorSpace);

	triangleDataTexture.flipY = false;
	triangleDataTexture.generateMipmaps = false;
	triangleDataTexture.needsUpdate = true;

	aabbDataTexture = new THREE.DataTexture(aabb_array,
		4096,
		4096,
		THREE.RGBAFormat,
		THREE.FloatType,
		THREE.Texture.DEFAULT_MAPPING,
		THREE.ClampToEdgeWrapping,
		THREE.ClampToEdgeWrapping,
		THREE.NearestFilter,
		THREE.NearestFilter,
		1,
		THREE.NoColorSpace);

	aabbDataTexture.flipY = false;
	aabbDataTexture.generateMipmaps = false;
	aabbDataTexture.needsUpdate = true;


	// scene/demo-specific uniforms go here
	pathTracingUniforms.tTriangleTexture = { value: triangleDataTexture };
	pathTracingUniforms.tAABBTexture = { value: aabbDataTexture };

} // end function initSceneData()



// called automatically from within the animate() function (located in InitCommon.js file)
function updateVariablesAndUniforms() 
{
	// INFO
	cameraInfoElement.innerHTML = "FOV: " + worldCamera.fov + " / Aperture: " + apertureSize.toFixed(2) +
		" / FocusDistance: " + focusDistance + "<br>" + "Samples: " + sampleCounter;

} // end function updateUniforms()



load_GLTF_Model(); // load model, init app, and start animating