public virtual Color Compute(
List<Light> lights, Object3D obj, V3 p, V2 uv
)
{
Color illumination = new Color(0, 0, 0);
foreach (Light l in lights) {
if (l.GetType().Name == "AmbientLight") {
illumination += ComputeAmbientLight(
(AmbientLight) l, obj, p, uv
);
}
else if (l.GetType().Name == "PointLight") {
illumination += ComputePointLight(
(PointLight) l, obj, p, uv
);
}
else if (l.GetType().Name == "DirectionalLight") {
illumination += ComputeDirectionalLight(
(DirectionalLight) l, obj, p, uv
);
}
}
return illumination;
}
/// Computes the diffuse and specular components of the Phong
/// reflection model for a directional light.
public override Color ComputeDirectionalLight(
DirectionalLight dL, Object3D obj, V3 p, V2 uv
)
{
V3 incidentVec = -dL.Direction;
return ComputeDiffuseSpecular(dL, obj, p, uv, incidentVec);
}
/// Computes the diffuse and specular components of the Phong
/// reflection model for a point light.
public override Color ComputePointLight(
PointLight pL, Object3D obj, V3 p, V2 uv
)
{
V3 incidentVec = pL.Position - p;
incidentVec.Normalize();
return ComputeDiffuseSpecular(pL, obj, p, uv, incidentVec);
}
public Ray(V3 origin, V3 direction, Object3D originObject = null)
{
Origin = origin;
Direction = direction;
Direction.Normalize();
OriginObject = originObject;
Distance = float.MaxValue;
}
private Color ComputeDiffuse(
Light l, V3 incidentVec, V3 normalVec, Object3D obj, V2 uv
)
{
Color diffuseIllu = new Color(0, 0, 0);
if (incidentVec * normalVec > 0.0f) {
diffuseIllu = obj.TextureColor(uv) * l.Intensity *
obj.Material.KDiffuse * (incidentVec * normalVec);
}
return diffuseIllu;
}
/// 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;
}
/// Renders one object.
private void RenderObject(Object3D obj)
{
for (float u = 0.0f ; u < 1.0f ; u += 0.001f) {
for (float v = 0.0f ; v < 1.0f ; v += 0.001f) {
V2 uv = new V2(u,v);
V3 p = obj.Point(uv);
V3 pScreen = new V3(
x: p.X,
y: Canvas.Height - p.Z,
z: p.Y
);
bool objectVisible = Set(pScreen);
if (objectVisible) {
Color illumination = Scene.IlluModel.Compute(
Scene.Lights, obj, p, uv
);
Canvas.DrawPixel(pScreen, illumination);
}
}
}
}
/// Computes the ambient component of the Phong reflection model for
/// an ambient light.
public override Color ComputeAmbientLight(
AmbientLight aL, Object3D obj, V3 p, V2 uv
)
{
return obj.TextureColor(uv) * aL.Intensity * obj.Material.KAmbient;
}
/// 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;
}
public override Color ComputeAmbientLight(
AmbientLight aL, Object3D obj, V3 p, V2 uv
)
{
return new Color(0, 0, 0);
}
public abstract Color ComputePointLight(
PointLight pL, Object3D obj, V3 p, V2 uv
);
public abstract Color ComputeDirectionalLight(
DirectionalLight dL, Object3D obj, V3 p, V2 uv
);
public abstract Color ComputeAmbientLight(
AmbientLight aL, Object3D obj, V3 p, V2 uv
);
public override Color ComputePointLight(
PointLight pL, Object3D obj, V3 p, V2 uv
)
{
return new Color(0, 0, 0);
}
public override Color ComputeDirectionalLight(
DirectionalLight dL, Object3D obj, V3 p, V2 uv
)
{
return new Color(0, 0, 0);
}
/// 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;
}
private Color ComputeSpecular(
Light l, V3 reflectedVec, V3 viewingVec, Object3D obj, V2 uv
)
{
Color specularIllu = new Color(0, 0, 0);
if (reflectedVec * viewingVec > 0.0f) {
specularIllu = l.Intensity * obj.Material.KSpecular *
Mathf.Pow(
reflectedVec * viewingVec,
obj.Material.Shininess
);
}
return specularIllu;
}
public override Color Compute(
List<Light> lights, Object3D obj, V3 p, V2 uv
)
{
return obj.TextureColor(uv);
}
