Question

I have a WebGL fragment shader that I am using to do raytracing. I pass in sphere and triangle data using textures. So far I’ve got 2 spheres and 3 triangles working. When I add the call to check interesection with a 4th triangle, the shader does not link, and calling getProgramInfoLog() just returns null.

Could the fragment shader be getting too big? Or do I need to look for another cause? How do I determine where the problem might be?

Here is a code snippet, commenting out any one of the checkTriangleIntersection calls causes the shader to link successfully.

checkTriangleIntersection(0.0, rayOrigin, rayDir, piOfNearest, normalOfNearest, colourOfNearest, distOfNearest);        
checkTriangleIntersection(1.0, rayOrigin, rayDir, piOfNearest, normalOfNearest, colourOfNearest, distOfNearest);
checkTriangleIntersection(2.0, rayOrigin, rayDir, piOfNearest, normalOfNearest, colourOfNearest, distOfNearest);
//checkTriangleIntersection(3.0, rayOrigin, rayDir, piOfNearest, normalOfNearest, colourOfNearest, distOfNearest);

Since all the calls are the same, except for the index, I thought that there would be nothing wrong with the code itself, but is there some kind of limit that I could be running up against?

I’m getting more then 30 FPS before I add the extra function call, and even when I do add the extra call, both the vertex and fragemnt shader compile OK.

Answer 1

I got rid of the issue by putting the calls to checkTriangleIntersection() into a for loop.