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Lighting, shadows and global illumination are still incredibly hard with voxels. And this is true for both Atomontage and Euclideon. Their demos look like reall

Lighting, shadows and global illumination are still incredibly hard with voxels. And this is true for both Atomontage and Euclideon. Their demos look like really over HDR'ed.

caffeineviking 8y ago
Not really, in fact it's the other way around. While rendering triangle meshes using rasterization (the "classic" way) is fast (because modern hardware is built for this), doing real-time light transport is a pain-in-the-ass, and involves a lot of inelegant (but very smart!) tricks (e.g. shadow mapping). On the other hand, we have ray tracing on triangle meshes, which is elegant, but really doesn't perform as well as rasterization, because you need a lot of rays to converge to a non-noisy result. The state-of-the-art global illumination renderers all use a hybrid approach. Either they reduce the triangle mesh so real-time Radiosity becomes viable (like in the Frostbite 2 engine), but these suffer from not being able to simulate specular surfaces as good. While the other approach is to discretize the mesh to a voxel representation and do Voxel Cone Tracing (VCT) (which is the same as ray tracing, but instead of shooting rays, you shoot "thick" rays, and get the incoming importance over an area), which produces non-noisy results, and can be done really fast. There is a reason why engines like Unreal Engine, Unity and Godot have started to implement VCT, and why a lot of research is being geared toward finding efficient ways to do scene voxelization (just look at the DICE/SEED thesis work proposals and you'll see that this is indeed true). The advantage of having an engine that only deals with voxels is that the techniques I've shown above can be done naturally, you can use a "pure" voxel approach instead of a hybrid. There is no need to convert triangle mesh scene to a voxel representation. My main worries with the method shown in the article is that doing animation (those not generated procedurally) using voxels is very hard. Also, the amount of memory needed to store a voxel scene is several orders of magnitude larger than a triangle mesh, even if you compress it, and worst of all, you need to store the animation as well, and depending on how that's done, can be a absolute nightmare (but I'm not up-to-date with the latest reserach there, maybe there are some fancy techniques that solve this problem).
Assossa 8y ago
Not at all. Lighting and shadows can be calculated the exact same way as polygons. As for GI, voxels are superior to polygons. If you look at all the real-time GI technologies, they are mostly voxel based. Ex: Nvidia VXGI

Lighting, shadows and global illumination are still incredibly hard with voxels. And this is true for both Atomontage and Euclideon. Their demos look like really over HDR'ed.

caffeineviking 8y ago

Not really, in fact it's the other way around. While rendering triangle meshes using rasterization (the "classic" way) is fast (because modern hardware is built for this), doing real-time light transport is a pain-in-the-ass, and involves a lot of inelegant (but very smart!) tricks (e.g. shadow mapping). On the other hand, we have ray tracing on triangle meshes, which is elegant, but really doesn't perform as well as rasterization, because you need a lot of rays to converge to a non-noisy result. The state-of-the-art global illumination renderers all use a hybrid approach. Either they reduce the triangle mesh so real-time Radiosity becomes viable (like in the Frostbite 2 engine), but these suffer from not being able to simulate specular surfaces as good. While the other approach is to discretize the mesh to a voxel representation and do Voxel Cone Tracing (VCT) (which is the same as ray tracing, but instead of shooting rays, you shoot "thick" rays, and get the incoming importance over an area), which produces non-noisy results, and can be done really fast. There is a reason why engines like Unreal Engine, Unity and Godot have started to implement VCT, and why a lot of research is being geared toward finding efficient ways to do scene voxelization (just look at the DICE/SEED thesis work proposals and you'll see that this is indeed true). The advantage of having an engine that only deals with voxels is that the techniques I've shown above can be done naturally, you can use a "pure" voxel approach instead of a hybrid. There is no need to convert triangle mesh scene to a voxel representation. My main worries with the method shown in the article is that doing animation (those not generated procedurally) using voxels is very hard. Also, the amount of memory needed to store a voxel scene is several orders of magnitude larger than a triangle mesh, even if you compress it, and worst of all, you need to store the animation as well, and depending on how that's done, can be a absolute nightmare (but I'm not up-to-date with the latest reserach there, maybe there are some fancy techniques that solve this problem).

Assossa 8y ago

Not at all. Lighting and shadows can be calculated the exact same way as polygons. As for GI, voxels are superior to polygons. If you look at all the real-time GI technologies, they are mostly voxel based. Ex: Nvidia VXGI