fixedAdvancedSparkSLScript.sca

// adam ferris found it:

#import <lights>
struct PhongMaterialParameters {
vec3 emission;
vec3 ambientFactor;
vec3 diffuseFactor;
vec3 specularFactor;
float shininess;
float occlusion;
};
vec3 applyPhong(
std::LightData light,
vec3 normal,
vec3 view,
PhongMaterialParameters material) {
vec3 reflected = -reflect(light.toLightDirection, normal);
float LdotN = dot(light.toLightDirection, normal);
float RdotV = max(dot(reflected, view), 0.0);
float diffuseFactor = max(LdotN, 0.0);
vec3 diffuse = material.diffuseFactor * (light.intensity * diffuseFactor);
float specularFactor = pow(RdotV, material.shininess) * step(0.0, LdotN); // do not light backface
vec3 specular = material.specularFactor * (light.intensity * specularFactor);
return material.occlusion * diffuse + specular;
}
// A material that uses the Phong shading model.
//
// @param [default=0.0, min=0.0, max=100.0] smoothness
void main( optional <std::Texture2d> diffuseTexture,
optional <std::Texture2d> normalTexture,
optional <std::Texture2d> specularTexture,
optional <std::Texture2d> emissiveTexture,
float smoothness,
out vec4 Position,
out vec4 Color) {
float shininess = mix(1.0, 100.0, pow(smoothness * 0.01, 2.0)); // non-linear mapping from [0,100] to [1,100]
// Attributes
vec2 uv = std::getVertexTexCoord();
vec4 n = normalTexture.sample(uv).valueOr(vec4(std::getVertexNormal(),0.0));
vec3 sampledNormal = normalize(std::getTangentFrame() * n.xyz * 2.0 - 1.0);
vec3 localNormal = sampledNormal;
vec4 localPosition = std::getVertexPosition();
// Material parameters
vec4 diffuseAndOpacity = diffuseTexture.sample(uv).valueOr(vec4(1.0));
vec4 specularAndShininess = specularTexture.sample(uv).valueOr(vec4(1.0));
PhongMaterialParameters material;
material.emission = emissiveTexture.sample(uv).rgb.valueOr(vec3(0.0));
material.ambientFactor = diffuseAndOpacity.rgb;
material.diffuseFactor = diffuseAndOpacity.rgb;
material.specularFactor = specularAndShininess.rgb;
material.shininess = clamp(specularAndShininess.a * shininess, 1.0, 100.0);
material.occlusion = 1.0;
// Screen-space position
Position = std::getModelViewProjectionMatrix() * localPosition;
// Camera-space normal, position, and view
vec3 csNormal = normalize(fragment(std::getNormalMatrix() * localNormal));
vec4 csPosition = fragment(std::getModelViewMatrix() * localPosition);
vec3 csView = normalize(-csPosition.xyz); // csCamera is at vec3(0,0,0)
// color
vec3 color = material.emission + material.ambientFactor * std::getAmbientLight().rgb;
if (std::getActiveLightCount() > 0) color += applyPhong(std::getLightData0(csPosition.xyz), csNormal, csView, material);
if (std::getActiveLightCount() > 1) color += applyPhong(std::getLightData1(csPosition.xyz), csNormal, csView, material);
if (std::getActiveLightCount() > 2) color += applyPhong(std::getLightData2(csPosition.xyz), csNormal, csView, material);
if (std::getActiveLightCount() > 3) color += applyPhong(std::getLightData3(csPosition.xyz), csNormal, csView, material);
Color = vec4(color, diffuseAndOpacity.a);
}