Questions about GPU particles

Hey UDN,

I was wondering if right out of the box Rocket can do things like in the following video for Batman.

GPU PhysX in Batman Arkham Asylum

I am especially interested to know if things like the paper and the massive amounts of destruction that you see in the video can be accomplished at a playable frame rate without having to add a lot of custom code. Does anyone have any ideas on the feasibility of getting all of the effect in the above video working in Rocket?

I can only speak to destruction. We do have APEX destruction integrated into UE4, and that should support pretty large numbers of bodies. We have an ‘asynchronous scene’ now, which runs bodies in it in another thread. Try it out! You can make a Destructible Mesh from a Static Mesh via the content browser context menu. This is a feature under heavy iteration so we would love to get feedback.

Thanks for the response James. Quick question, do I still need to use the APEX labs tool to cut up the mesh and import or is it still like using the fracture tool from UE3?

You can do either- import from PhysXLab or cut up from existing StaticMesh right in the editor. You can also manually fracture the object in Max/Maya and import that FBX as ‘level 1 fracture’ in the Destructible Mesh Editor tool in the engine.

Holly snikes that is freaking awesome. I will have to check that out today. Thanks for the heads up.

Its not yet possible in Rocket. I have added a request for PhysX Particles here. They said they are discussing about it.

Well I am not really interested in the GPU particles(Epics custom solution looks really good IMO) I would really like to know if things like the amount of destruction you see onscreen is possible and if its possible to do things like the interactive paper. I am going to be doing some testing today but I really just wanted to get a heads up if this is even going to work.

GPU Particles has nothing to do with PhysX particles. Interactive paper, Interactive smoke are PhysX particles and massive amount of destruction are PhysX Destructions. I think in Rocket you can create small level of destruction’s using Destructible Mesh(Fractured Mesh in UDK) but i believe it has its limitations. Would love to hear from one of the Epic staff about this.

Doesn’t Rocket support APEX destruction? I was under the impression that it does so that would take care of the destruction part. The GPU particles that NVIDIA created would probably act in a similar manner to the way that Epic did their system as the main goal is get them all on the GPU for performance reasons.

I am pretty sure that I could get the interactive smoke working using Vector Fields but I am not sure if you can attach a Vector Field to an object that is moving. I remember reading somewhere that Vector Fields can only be static at the moment but I am not sure if that has changed or not.

The paper is the one thing that I am really not sure how to do as I currently do not see a way to get that working as it looks like there is no cloth option like they had in the UT3 editor. I am thinking that maybe it could be done via APEX clothing but that sounds like it might be a bit over kill for that system(I am also not sure if APEX clothing is even supported yet). I am going to try and see what I can and cannot do with the current system and hope that Epic does get something like the what NVIDIA had into Rocket.

I think APEX is included with Rocket although am not sure.

Vector fields dont have any kind of interaction. They are just grid of vectors that controls how the particles move. You can place a Global Vector Field which is dynamic and can be moved any time.

Yes I understand how Vector fields work, I am just wondering if it’s at all possible to have them attached to your pawn so that your pawn will “push” particles around when moving through them kind of like Batman did in the video in my first post.