Get Pixel Height (PostProcess)

[Gandi]

Is there a texture/buffer which stores the height-data of the scene, or is there any other way of getting the y-position of a pixel in the PostProcess shader?

or is it possible to get all the coords (x/y/z) of a specific point?

[klepto2]

this is how to calculate the pixel position in world coords:

 

//needed uniforms in eg postfilter.frag
uniform vec3 cameraposition;
uniform mat4 cameramatrix;

vec3 screencoord;
vec4 fogcoord;

screencoord = vec3(((gl_FragCoord.x/buffersize.x)-0.5) * 2.0,((-gl_FragCoord.y/buffersize.y)+0.5) * 2.0 / (buffersize.x/buffersize.y),DepthToZPosition( depth ));
screencoord.x *= screencoord.z;
screencoord.y *= -screencoord.z;

vec4 worldpos = vec4(screencoord,1.0) * cameramatrix;

worldpos += vec4(cameraposition,0.0);

 

Needed Shader variables to be set

SetShaderVec3(postfilter,"cameraposition",camera.position);
SetShaderMat4(postfilter , "cameramatrix" , GetEntityMatrix(Camera).Inverse() ) ;

[Gandi]

Thanks a lot!

works fine!

btw there are built in uniforms as "cameraposition" and "camerainversemat4" where i dont even have to parse the variables to the shader

[klepto2]

yeah, I wasn't sure in which version I have implemented it and so i have added these parameters as i haven't looked if they are provided by the engine.