private Color RenderRay(RayData rayData)
{
float depth = 0;
for (int step = 0; step < MaxMarchingSteps; step++)
{
Vector3 samplePoint = rayData.EyePosition + depth * rayData.RayDirection;
float distance = SphereSDF(samplePoint);
if (distance < rayData.Epsilon)
{
// Since our sphere located in the center of the world we can easlity get normal of
// the point where we touching sphere by simple normalization
Vector3 normal = samplePoint.normalized;
// TODO: implement Specualr and Ambient sampling
Color color = GetDiffuseColor(normal, rayData.LightingRig, hitPoint: samplePoint);
return(color);
}
depth += distance;
// Make sure we are not going too far from sphere
if (depth > _distanceToSphere * 2)
{
break;
}
}
return(Color.black);
}
// TODO: implement split texture rendering for Diffuse, Alpha & Specular (now supported only Combined)
// TODO: implement viriable view position (now supported only along Z axis)
public override void Render(MatCapSnapshot matCapSnapshot, LightingRig lightingRig, CameraRuntimeRef cameraRef)
{
Texture2D combined = matCapSnapshot.Combined;
Color[] pixels = combined.GetPixels();
// Min distance to sphere caluclated according to texel size
float epsilon = GetEpsilon(combined.width, combined.height);
// Pixels layed out left to right, bottom to top
for (int row = combined.height - 1; row >= 0; row--)
{
for (int col = 0; col < combined.width; col++)
{
var rayData = new RayData();
rayData.RayDirection = GetRayDirection(combined.width, col, combined.height, row, cameraRef);
rayData.LightingRig = lightingRig;
rayData.EyePosition = new Vector3(0, 0, -_distanceToSphere);
rayData.Epsilon = epsilon;
// TODO: use new Unity data oriented desing with ECS and Burst
// This task could be parallelized
int index = row * combined.width + col;
pixels[index] = RenderRay(rayData);
}
}
combined.SetPixels(pixels);
combined.Apply();
}