> Added a SpotLight only to the D3D pipeline currently. > > ### API discussion points > > - [X] Added `SpotLight` as a subclass of `LightBase`. However, it could also > be a subclass of `PointLight` as it's a point light with direction and extra > factors. I saw that `scenario.effect.light.SpotLight` extends its respective > `PointLight`, but it's not a perfect analogy. In the end, I think it's a > questions of whether `PointLight` will be expanded in a way which doesn't not > suit `SpotLight`, and I tend to think that the answer is no. > > - [X] The inner and outer angles are the "diameter angles" as shown > [here](https://docs.microsoft.com/en-us/windows/win32/direct3d9/light-typeshttps://docs.microsoft.com/en-us/windows/win32/direct3d9/light-types). > I, personally, find it more intuitive that these are the "radius angles", > so half these angles, as used in the spotlight factor formula. Do you think I > can change this or do you prefer the current definition of the angles? > > - [x] The current implementation uses an ad-hoc direction property (using a > `Point3D`). It crossed my mind that we could use the rotation transforms of > the node to control the direction instead, just like we use the > translation/layout of the node to get the position (there is an internal > Affine3D transform for lights, not sure why `AmbientLight` needs it). > Wouldn't that make more sense? When I rotate the light I would expect to see > a change in direction. > > ### Implementation discussion points > > - [ ] I've gotten advice from a graphics engineer to treat point lights as > spot lights with a 360 degrees coverage, which simplifies a few places. We > can still try to optimize for a point light by looking at the light > parameters: `falloff = 0` and `outerAngle = 180`. These possible optimization > exist in `ES2PhongShader.java` and `D3DMeshView.cc`, and in the > pixel/fragment shaders in the form of 3 different ways to compute the > spotlight factor (the `computeLightN` methods). We need to check which of > these give the best results. > > ## Performance > > Testing 3 point lights and comparing this branch with `master` using a 1000 > division sphere, 200 meshes, and 5000 meshes. > Using an AMD RX 470 4GB GPU. > > In this branch, there is a possible CPU optimization for checking the light > type and using precalculated values (in `D3DMeshView.cc` for d3d and > `ES2PhongShader.java` for opengl). On the GPU, I tried 3 ways of computing > the spotlight factor contributions (`computeSpotlightFactor`, > `computeSpotlightFactor2` and `computeSpotlightFactor3`) trying out different > branching and shortcuts. > > ### Results > The CPU "optimizations" made no difference, which is understandable > considering it will not be the bottleneck. We can remove these if we want to > simplify, though maybe if we allow a large number of lights it could make a > difference (I doubt it). I don't have a strong preference either way. > > The sphere 1000 tests always gave max fps (120 on Win and 60 on Ubuntu). > > **Win 10** > Compared with the `master` branch, this patch shows 5-10 fps drop in the mesh > 200 test and ~5 in the mesh 5000 test. I repeated the tests on several > occasions and got different results in terms of absolute numbers, but the > relative performance difference remained more or less the same. Out of the 3 > `computeSpotlightFactor` methods, `computeSpotlightFactor3`, which has no > "optimizations", gives slightly better performance. > > **Ubuntu 18** > The mesh 200 test always gave 60 fps because it is locked to this fps, so we > can't measure the real GPU performance change. > The mesh 5000 test shows 2-6 fps drop from master, with > `computeSpotlightFactor` > `computeSpotlightFactor2` > > `computeSpotlightFactor3` at in terms of performance (~2 fps difference each). > > **Conclusion**: we can expect a 5 fps drop more or less with 3 point lights. > `computeSpotlightFactor3` on d3d and `computeSpotlightFactor` on opengl gave > the best performances.
Nir Lisker has updated the pull request incrementally with one additional commit since the last revision: Addressed doc review comments ------------- Changes: - all: https://git.openjdk.java.net/jfx/pull/334/files - new: https://git.openjdk.java.net/jfx/pull/334/files/0bdb7cdd..1f17f8ba Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=334&range=20 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=334&range=19-20 Stats: 12 lines in 1 file changed: 1 ins; 0 del; 11 mod Patch: https://git.openjdk.java.net/jfx/pull/334.diff Fetch: git fetch https://git.openjdk.java.net/jfx pull/334/head:pull/334 PR: https://git.openjdk.java.net/jfx/pull/334
