Okay, few things.
Been looking into SE's parallax shaders. There's one bug in the renderer code that I fixed already (game does not update view position vector for parallax shader technique, so its got random data, which is why if you create a parallax lighting shader mesh it has jitter between random broken states).
But the parallax in the pixel shaders is incorrect, it is using model space view direction vector to calculate parallax, instead of tangent space, I think. (not 100% sure on this, my knowledge of graphics programming is limited)
There are 72 parallax technique pixel shaders, the parallax code is at the start, one example shader:
Code: Select all
// normalize view direction vector (v6)
r0.x = dot(v6.xyz, v6.xyz);
r0.x = rsqrt(r0.x);
r0.xy = v6.xy * r0.xx;
// sample parallax texture (sampler 3)
r0.z = TexHeightSampler.Sample(HeightSampler, v1.xy).x;
// calculate parallax offset
r0.z = r0.z * 0.0800 + -0.0400;
r0.xy = r0.xy * r0.zz + v1.xy;
// sample diffuse (sampler 0) + normal (sampler 1)
r1.xyzw = TexDiffuseSampler.Sample(DiffuseSampler, r0.xy).xyzw;
r0.xyzw = TexNormalSampler.Sample(NormalSampler, r0.xy).xyzw;
v3/v4/v5 should have the model->tangent space transformation matrix so the patch would be to transform the view direction vector with v3/v4/v5
Code: Select all
// normalize view direction vector (v6)
r0.x = dot(v6.xyz, v6.xyz);
r0.x = rsqrt(r0.x);
r0.xy = v6.xy * r0.xx;
// calculate and normalize tangent space view direction
float4 r10;
r10.x = dot(v3.xyz, v6.xyz);
r10.y = dot(v4.xyz, v6.xyz);
r10.z = dot(v5.xyz, v6.xyz);
r10.w = dot(r10.xyz, r10.xyz);
r10.w = rsqrt(r10.w);
r10.xyz = r10.xyz * r10.www;
// sample parallax texture (sampler 3)
r0.z = TexHeightSampler.Sample(HeightSampler, v1.xy).x;
// calculate parallax offset using tangent space view direction vector
r0.z = r0.z * 0.0800 + -0.0400;
r0.xy = r10.xy * r0.zz + v1.xy;
// sample diffuse (sampler 0) + normal (sampler 1)
r1.xyzw = TexDiffuseSampler.Sample(DiffuseSampler, r0.xy).xyzw;
r0.xyzw = TexNormalSampler.Sample(NormalSampler, r0.xy).xyzw;
Obviously in this example you can see that r0.xyz is immediately overwritten with the normal sample so it's not necessary to create a new variable to store the transformed view direction vector, but in some of the parallax shaders r0 is used later on without being overwritten by the normal sampler so it's not safe in all situations.
Would this be too annoying to patch in ENB? I'm probably going to throw together code to patch it myself as an skse plugin but it would probably have some ENB incompatibility since these 72 shaders might not match anymore.
I can provide an example mesh to show in-game if you want.
