public override float Intersect(SLRay currentRay)
{
float normDotRay = pNormal.Dot(currentRay.Direction);
if (normDotRay == 0)
return -1;
float d = -(pNormal.Dot(currentRay.Origin) - Offset) / normDotRay;
if (d < 0)
return -1;
else
return d;
}
static void GetClosestIntersection(ref SLRay ray)
{
foreach(SLRayPrimitive primitive in RayObjects)
{
float d = primitive.Intersect(ray);
if (d < ray.ClosestPointDistance && d > 0)
{
ray.ClosestPrimitive = primitive;
ray.ClosestPointDistance = d;
}
}
ray.ClosestPoint = ray.Origin + (ray.Direction * ray.ClosestPointDistance);
}
public override float Intersect(SLRay currentRay)
{
SLVector3f e = currentRay.Origin;
SLVector3f o = position;
SLVector3f d = currentRay.Direction;
SLVector3f rayToSphereOrigin = o - e;
float b = rayToSphereOrigin.Dot(d);
float h = radius * radius + b * b - rayToSphereOrigin.x * rayToSphereOrigin.x - rayToSphereOrigin.y * rayToSphereOrigin.y - rayToSphereOrigin.z * rayToSphereOrigin.z;
// Early out
if (h < 0)
return -1;
h = b - (float)Math.Sqrt(h);
if (h < 0)
return -1;
else return h;
}
public abstract float Intersect(SLRay currentRay);
static Color SetPixelColor(SLRay ray, int depth)
{
// Get closest intersection IF ANY
GetClosestIntersection(ref ray);
// Return if the ray didn't hit anything
if (ray.ClosestPointDistance >= SLRay.Max_Distance || ray.ClosestPrimitive == null)
return BG_COLOR;
// Set ambient light
float r = LaR * ray.ClosestPrimitive.PrimitiveColor.R;
float g = LaG * ray.ClosestPrimitive.PrimitiveColor.G;
float b = LaB * ray.ClosestPrimitive.PrimitiveColor.B;
// Add contributions of each light
SLVector3f normal = ray.ClosestPrimitive.PointNormal(ray.ClosestPoint);
SLVector3f viewDir = -ray.Direction;
foreach (SLLight light in Lights)
{
SLVector3f lightDir = new SLVector3f();
float lightDistance;
// Find light direction and distance
lightDir = light.position - ray.ClosestPoint;
lightDistance = lightDir.Magnitude();
lightDir.Normalize();
SLRay pointToLight = new SLRay(ray.ClosestPoint + (lightDir * TINY), lightDir);
pointToLight.ClosestPointDistance = lightDistance;
GetClosestIntersection(ref pointToLight);
if (pointToLight.ClosestPrimitive != null)
continue;
// DIFFUSE LIGHTING
float lDotN = normal.Dot(lightDir);
// Clamp
if (lDotN <= 0)
continue;
float diffColorContrR = (light.color.R * lDotN)/255.0f;
float diffColorContrG = (light.color.G * lDotN)/ 255.0f;
float diffColorContrB = (light.color.B * lDotN)/ 255.0f;
// Add this light's diffuse contribution to our running totals
r += diffColorContrR * ray.ClosestPrimitive.PrimitiveColor.R;
g += diffColorContrG * ray.ClosestPrimitive.PrimitiveColor.G;
b += diffColorContrB * ray.ClosestPrimitive.PrimitiveColor.B;
if (MATERIAL_SPECULAR_COEFFICIENT > TINY)
{
// Specular component - dot product of light's reflection vector and viewer direction
// Direction to the viewer is simply negative of the ray direction
SLVector3f lightReflectionDir = normal * (lDotN * 2) - lightDir;
float specularFactor = viewDir.Dot(lightReflectionDir);
if (specularFactor > 0)
{
// To get smaller, sharper highlights we raise it to a power and multiply it
specularFactor = MATERIAL_SPECULAR_COEFFICIENT * (float)Math.Pow(specularFactor, MATERIAL_SPECULAR_POWER);
// Add the specular contribution to our running totals
r += MATERIAL_SPECULAR_COEFFICIENT * specularFactor * ray.ClosestPrimitive.PrimitiveColor.R;
g += MATERIAL_SPECULAR_COEFFICIENT * specularFactor * ray.ClosestPrimitive.PrimitiveColor.G;
b += MATERIAL_SPECULAR_COEFFICIENT * specularFactor * ray.ClosestPrimitive.PrimitiveColor.B;
}
}
if (depth < MAX_DEPTH && MATERIAL_REFLECTION_COEFFICIENT > TINY)
{
// Set up the reflected ray - notice we move the origin out a tiny bit again
SLVector3f reflectedDir = ray.Direction.Reflection(normal);
SLRay reflectionRay = new SLRay(ray.ClosestPoint + reflectedDir * TINY, reflectedDir);
// And trace!
Color reflectionCol = SetPixelColor(reflectionRay, depth + 1);
// Add reflection results to running totals, scaling by reflect coeff.
r += MATERIAL_REFLECTION_COEFFICIENT * reflectionCol.R;
g += MATERIAL_REFLECTION_COEFFICIENT * reflectionCol.G;
b += MATERIAL_REFLECTION_COEFFICIENT * reflectionCol.B;
}
}
// Clamp
if (r > 255) r = 255;
if (g > 255) g = 255;
if (b > 255) b = 255;
// Take care of NaN
if (r < 0) r = 0;
if (g < 0) g = 0;
if (b < 0) b = 0;
return (Color.FromArgb(255, (int)r, (int)g, (int)b));
}
static Color Render(int x, int y)
{
float sx = (x / WIDTH_DIV_2 - 1.0f);
float sy = (1.0f - y / HEIGHT_DIV_2);
SLVector3f u = screenU * sx;
SLVector3f v = screenV * sy;
SLVector3f direction = u + v - dir;
direction.Normalize();
SLRay posRay = new SLRay(EYE, direction);
return SetPixelColor(posRay, 0);
}