Hi All,
I am trying to create model’s outline using PostProcessStage. I refers the article: Unity Outline Shader Tutorial - Roystan . So I need normal information for my purpose.
Currently, I can compute normal by use the function. The function is get from AmbientOcclusionGenerate.glsl: cesium/packages/engine/Source/Shaders/PostProcessStages/AmbientOcclusionGenerate.glsl at main · CesiumGS/cesium · GitHub
vec3 getNormalXEdge(vec2 positionSC)
{
// Find the 3D surface positions at adjacent screen pixels
vec3 positionEC = pixelToEye(positionSC);
vec3 positionLeft = pixelToEye(positionSC + vec2(-1.0, 1.0));
vec3 positionRight = pixelToEye(positionSC + vec2(1.0, -1.0));
vec3 positionUp = pixelToEye(positionSC + vec2(1.0, 1.0));
vec3 positionDown = pixelToEye(positionSC + vec2(-1.0, -1.0));
// Compute potential tangent vectors
vec3 dx0 = positionEC - positionLeft;
vec3 dx1 = positionRight - positionEC;
vec3 dy0 = positionEC - positionDown;
vec3 dy1 = positionUp - positionEC;
// The shorter tangent is more likely to be on the same surface
vec3 dx = magnitude(dx0) < magnitude(dx1) ? dx0 : dx1;
vec3 dy = magnitude(dy0) < magnitude(dy1) ? dy0 : dy1;
return normalize(cross(dx, dy));
}
However, the output is not good because the accuracy of normal is not good. I am finding the way to compute normal accurately or the way to pass the normal information from custom shader stage to post process stage. Do you have any idea ? Thanks a lot!
This is my current result:
