On Mon, 15 Aug 2022 10:03:11 GMT, Nir Lisker <nlis...@openjdk.org> wrote:
>> Command to run the system test: >> `gradle -PFULL_TEST=true -PUSE_ROBOT=true systemTests:test --tests >> test.robot.test3d.PointLightIlluminationTest` >> >> I ran all the tests, only above test failed: >> Command to run all the system tests: `gradle -PFULL_TEST=true >> -PUSE_ROBOT=true systemTests:test` > > First of all, I found that the mistake was in the shortcut branch of the > shader: it was using the light direction instead of the vector to the light > (incident ray), so in the code I need to replace `dot(n, -lightDir)` with > `dot(n, -l)`, like is done in the full computation branch. Then the test > passes with the `0` input for no-attenuation. Thanks. > > Then I looked at the computation some more and I found something in the > computation of the specular component. According to the theory, both in > online sources and in the `PhongMaterial` class doc, the computation should > be: > `R . V` where `V` is the vector to the eye/cam and `R` is the reflection > vector computed by `R = 2(N . L)N - L`, or using the > [reflect](https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-reflect) > HLSL function, `R = -reflect(N, L)`. So the shader files should look > something like this: > > float3 refl = reflect(l, n); > s = ... dot(-refl, e); // e is the vector to the eye, like V > > However, looking at the shader files, [already from > legacy](https://github.com/openjdk/jfx/blob/c420248b9b459efcfbd3657170d9be0b96b5fb38/modules/javafx.graphics/src/main/native-prism-d3d/hlsl/psMath.h), > the vectors are switched: > > float3 refl = reflect(e, n); > s = ... dot(-refl, l); > > It looks like the specular computation was wrong from the start. > > I tested the visuals on the `master` branch before and after swapping the `l` > and `e` vectors and I see no difference in the specular reflection. Rather > odd. Will need to look into this more. > > The same mistakes are coded into the glsl shaders too, so I should fix the > one you found at the very least. @kevinrushforth maybe you can take a look at this too. ------------- PR: https://git.openjdk.org/jfx/pull/789
