Will raytracing support animations and mesh manipulation?

This is a very important feature for me, so I'm curious if this is possible or will be possible soon..
excerpt from docs:
HDRP ray tracing in Unity 2019.3 has the following limitations:

• Does not support deformers (skin, vertex animation).
• Does not support VFX and Terrain.
• Does not support several of HDRP's Materials. This includes Hair, StackLit, Eye, and AxF Materials.
• Does not have correct culling for shadows. It uses frustum culling instead.

Thank you.

 

Seb Lagarde, thank you so much for your response! Skinning for raytracing 2020.1 is an exciting feature. Could that mean manipulating mesh.vertices array could be possible with 2020.1 raytracing? The meshes in my game have scripts that deform meshes via mesh.vertices. Thank you for your help.

 

If you deform your mesh via c# code and not from shaders, I'd assume it would work already in 2019.3. But vertex offset via shaders for sure doesn't work on 2019.3 or 2020.1 (I've tested and it's confirmed to not be among supported functionality atm).

For skinned meshes, the support is on 8.0.1 which you can find in package manager now while using 2020.1.

 

How we are supposed to use Raytracing when we have animated vegetation and water? Skinned mesh is not an option and doing it via C# also not, HDRP is already very CPU bound, so you are supposed to put more workload to the GPU.
What does the Nvidia docs say regarding this topic? Is it not possible at all?

 

It's possible since UE4 does support this (vertex offset is called "World Position Offset" on UE material graph).

 

Really frustrating Unity lacks behind.

 

Is there any plans on supporting raytracing with vertex offset done via shader graph?

 

@Matjio I noticed that most of the features in this thread have either landed, or are being tracked on the HDRP roadmap (productboard) because you added them. Thank you for this, and the new roadmap hub that just launched is excellent!

There is one major item not yet on the roadmap. Can an item be created on the HDRP roadmap for this? i.e. "Raytracing support of Vertex Position Offset"

This a must have for raytraced rendering of animated foliage, and many other use cases with anything interesting in the vertex shader stage.

Here is the equivalent feature in action in UE4 that @rz_0lento mentioned, accessible by enabling "Evaluate World Position Offset" on the RayTracing settings of an Actor

Documentation: https://docs.unrealengine.com/en-US...yTracing/RayTracingSettings/index.html#actors

And here is an example of a Unity shader graph with this technique that does not currently work with raytracing. Any shader or shader graph that sets the vertex position at all, really as far as I know:

Thank you and happy GDC 2021!

 

I do love that Hybrid is coming (I've tested it early on as can be seen on the PR comments) and it sure helps for now. It means that we can now fallback to old style screen space effects for things that are not on RTAS (which again is way better than the old setup). That being said I still hope in future we can get vertex animations on real RT reflections as it clearly is possible to do (as seen happening on competing game engine). I can imagine it being hard to sell hybrid for gamers where they toggle expensive RT reflection option on game and they still see screenspace reflections there for things they care about... It's not ideal and is more like temporary solution IMHO.

Just to clarify this for people just hearing about the new hybrid mode, you basically now have a decision to make beforehand: do you want your mesh renderer to go to RTAS (which means raytracing works for static meshes, alembic animation and skeletal meshes) or if you don't use RT for that mesh at all and then the screenspace effects work for everything, including things that RT currently doesn't support (which are mainly particles, decals, terrain and vertex animation). Hybrid mode then picks between screenspace and raytraced effect on these meshes based on your design decisions.