void PlaneContactShadow_float(float rand, float3 position, float dist, float depth, out float shadowAmount) { #if SHADERGRAPH_PREVIEW shadowAmount = 0; #else const float STAR_ANGLE = 1.7; const int TOTAL_STEPS = 10; shadowAmount = 0; Light mainLight = GetMainLight(); float3 direction = mainLight.direction; float3 dirX = cross(direction, float3(0, 1, 0)); // Unit vector at right angle to light direction dirX = length(dirX) == 0 ? float3(1, 0, 0) : normalize(dirX); //edge case incase the light direction is completely vertical float3 dirY = cross(direction, dirX); // Unit vector at right angle to the light direction and dirX for (int i = 0; i < TOTAL_STEPS; i++) { //"normal" is a vector that rotates STAR_ANGLE radians around the light direction every iteration; it faces opposite the light direction and //is at a sharp angle with the light direction. This is to create the blurring effect. The starting orientation of the vector //is randomized using the "rand" input. float3 normal = -direction + (cos(i * STAR_ANGLE + rand) * dirX + sin(i * STAR_ANGLE + rand) * dirY) * 0.3; //by multiplying the step distance by the number of iterations (i) pixels that are further from the object will also recieve shadow, but less. float3 posStep = position - normal * i * 0.1 * dist; // Get the XY position of the projected position to be checked against the depth texture float4 newPos = mul(UNITY_MATRIX_VP, float4(posStep, 1.0)); newPos /= newPos.w; #if defined(SHADER_API_GLES3) || defined(SHADER_API_GLES) || defined(SHADER_API_GLCORE) newPos *= float4(0.5, 0.5, 1, 1); newPos += float4(0.5, 0.5, 0, 0); #else newPos *= float4(0.5, -0.5, 1, 1); newPos += float4(0.5, 0.5, 0, 0); #endif // Prevent the depth texture values from bleeding from one side to the other newPos = clamp(newPos, 0, 0.999); //Get the view space depth value of our projected point float3 newPosView = mul(UNITY_MATRIX_V, float4(posStep, 1.0)); // Compare the view space depth of our projected point to the depth texture value at the same XY location float depthCompare = saturate(dist - abs(-newPosView.z - LinearEyeDepth(SHADERGRAPH_SAMPLE_SCENE_DEPTH(newPos.xy), _ZBufferParams))); //scale by 2 divided by the total number of steps squared, the total number of steps minus i, and scale inversely by dist shadowAmount += 2.0 / (TOTAL_STEPS * TOTAL_STEPS) * (TOTAL_STEPS - i) * depthCompare / dist; } #endif }