erichlof
commented
2 years ago Hello @JustLexxy , Yes it is possible to not use any blue noise at all. Locate this line inside the large main() function inside of the PathTracing fragment shader file (which is written in the glsl language): vec2 pixelOffset = uFrameCounter < 150.0 ? vec2( tentFilter(rand()), tentFilter(rand()) ) : vec2( tentFilter(rng()), tentFilter(rng()) ); And change it to read instead: vec2 pixelOffset = vec2( tentFilter(rng()), tentFilter(rng()) );
The rand() function relies on the BlueNoise texture to produce random numbers between 0.0 and 1.0, whereas the rng() function computes the random numbers (also in the range of 0.0 to 1.0) all on its own. It produces pretty high quality white noise. As above, you will need to go through all glsl shader code for your own particular demo/scene and do a search and replace from rand() to rng(). Most if not all rand() will be found in the main() function as well as the CalculateRadiance() function. Every demo/scene will have a shader with these 2 functions at least. The final image output of the white noise rng() functions should look very similar to the blue noise rand() functions, but maybe won't look as smooth on the first animation frame, or might not converge as fast.
If you successfully change all of the occurrences of rand() to rng(), you can then go through and comment out any lines dealing with the blue noise texture itself, such as the following line, also located in the PathTracing shader's main() function: randVec4 = texelFetch(tBlueNoiseTexture, ivec2(mod(gl_FragCoord.xy + floor(uRandomVec2 * 256.0), 256.0)), 0);
In InitCommon.js, you could also get rid of the following lines, in order to avoid loading in the supplied 256x256 RGBA blue noise texture: // blueNoise texture used in all demos blueNoiseTexture = new THREE.TextureLoader().load('textures/BlueNoise_RGBA256.png'); blueNoiseTexture.wrapS = THREE.RepeatWrapping; blueNoiseTexture.wrapT = THREE.RepeatWrapping; blueNoiseTexture.flipY = false; blueNoiseTexture.minFilter = THREE.NearestFilter; blueNoiseTexture.magFilter = THREE.NearestFilter; blueNoiseTexture.generateMipmaps = false;
Pardon me if you already know this but it has been shown over the last 5 years or so that blue noise is preferable to white noise in path tracing. Path tracing requires many random numbers (usually in the 0.0 to 1.0 range) at every step of the way, from camera ray spawning, to sampling the camera lens (for depth of field effects), to material sampling (like diffuse surfaces), to shadow-ray sampling (producing smoother soft shadows). Blue noise beats white noise in almost every category. Not sure why you would want to disable blue noise, but at any rate, what I outlined in the above paragraphs should do the trick.
Let me know if you have any more questions or issues compiling. :) -Erich
JustLexxy
dafhi
Is it possible to remove the blue noise? I tried modifying a few things to try and remove the blue noise, but it either does nothing or the code doesn't compile. Do you know/have a fix to remove it? Thanks!