‘the flickering is very fast and constant’ That’s Sad news.
I’ve always had this issue,but only for a few seconds when the patch was starting.This behavior is now happening extremely rarely and randomly on my three years old machine : IntelCore2Duo T7200, Nvidia GeForce 7700, XPx86
Here’s another approach brought to me by toneburst that would probably remove this spiky behavior.Source code: 3d perlin vertex noise glsl sourcecode
It uses a lookup texture to generate the noise but unfortunately requires texture lookup in the Vertex Shader, which still only works on NVIDIA GPUs.
As it was not possible to access the tex2D outside the pixel shader Tonfilm was kind enough to show me how to do it using the tex2Dlod function.
also seeing the strange spikes, i had quick look at your noise3D function. and without understanding what it does i stumbled over this line at its very beginning:
v = v + float3(10000.0, 10000.0, 10000.0); // hack to avoid negative numbers
ahm, there is this other very common hack to avoid negative numbers which goes like this:
v = v + abs(v);
and seems to get rid of the spikes on noisevelvety…