/// Computes the diffuse and specular components of the Phong
/// reflection model.
/// @Note Avoids code duplication in ComputePointLight and
/// ComputeDirectionalLight.
private Color ComputeDiffuseSpecular(
Light l, Object3D obj, V3 p, V2 uv, V3 incidentVec
)
{
V3 normalVec = obj.Normal(p, uv);
V3 reflectedVec = incidentVec.ReflectedVector(normalVec);
reflectedVec.Normalize();
V3 viewingVec = CameraPos - p;
viewingVec.Normalize();
Color diffuseIllu = ComputeDiffuse(
l, incidentVec, normalVec, obj, uv
);
Color specularIllu = ComputeSpecular(
l, reflectedVec, normalVec, obj, uv
);
return diffuseIllu + specularIllu;
}
/// Recursivly raytrace to get the color resulting from the refracted
/// light component for the specified collisionPoint.
private Color RefractionColor(
V3 incidentVec, V3 collisionPoint, V2 collisionUV,
Object3D collidedObj, int depth
)
{
if (!collidedObj.Material.IsTransparent()) { return Color.Black; }
V3 normal = collidedObj.Normal(collisionPoint, collisionUV);
Ray refractionRay = new Ray(
origin: collisionPoint,
direction: incidentVec.RefractedVector(
normalVec: normal,
n1: Scene.RefractiveIndex,
n2: collidedObj.Material.RefractiveIndex
),
originObject: null
);
Color refractionColor = Raytrace(refractionRay, depth - 1);
if (refractionColor == null) { return Color.Black; }
return collidedObj.Material.Transparency * refractionColor;
}
/// Recursivly raytrace to get the color resulting from the reflected
/// light component for the specified collisionPoint.
private Color ReflectionColor(
V3 incidentVec, V3 collisionPoint, V2 collisionUV,
Object3D collidedObj, int depth
)
{
if (!collidedObj.Material.IsReflective()) { return Color.Black; }
V3 normal = collidedObj.Normal(collisionPoint, collisionUV);
Ray reflectionRay = new Ray(
origin: collisionPoint,
direction: incidentVec.ReflectedVector(normal),
originObject: collidedObj
);
Color reflectionColor = Raytrace(reflectionRay, depth - 1);
if (reflectionColor == null) { return Color.Black; }
return collidedObj.Material.Reflection * reflectionColor;
}