Calculate Lighting for whole scene Like Unreal Engine

[Jacolath]

I think n nice feature would be to calculate the Lighting (or even just GI) for the whole scene (or a selected area - maybe within bounding box) so that you can then quickly generate multiple perspectives from that area. One of the great appeals of Unreal Engine at the stage is that you can generate many perspectives for you client that they can use in all sorts of ways. I'm assuming the UHD Cache would be easy to save but was wondering if it would be somehow possible to save the Path Tracing information. For example when I render with a spherical 360 cam for VR a lot of the lighting is calculated for the whole space. Would it not be possible to save that and then only render the raytraced passes like reflection and refraction from the different angles? I'm assuming the additional angles would render really fast.

Thoughts?

[romullus]

Lightfield? Yes please, we need that in V2 :]

[Ondra]

Hi,
what you are describing is basically an irradiance cache/radiosity/other similar methods. There is unfortunately no way to have those with practical speed without sacrificing quality. Any glossy material is view-dependent and cannot be precomputed. Overall, this would be basically creating Corona realtime (game) engine, which is currently out of our scope.

[maru]

You can try Unreal Datasmith / Unreal Studio - it basically allows to export a scene from 3ds Max to UE with a single click - https://www.unrealengine.com/en-US/blog/introducing-datasmith-a-workflow-toolkit-for-unreal-engine
As far as I know it supports Corona Renderer already, but I have not tested it yet.

[rambambulli]

@jocalath, it is pretty easy to bake all the lights in maps and place the bakes on temporary objects in Max. I attached a test I made half a year ago to test bright white corona-lightmaps and glass door reflections in Unreal. Maybe this is helping you?

I want the same as you for a long time. I, therefore, use a somewhat desperate workaround.  I bake lightmaps with corona, place as an emissive map on a temporary corona material, placed on a cloned, temporary object. These temp objects I import in Unreal with Unreal Studio (works fast).

It is not a perfect workflow I have some issues with combining the lightmaps and dark textures but I get good enough results which I can share with my clients.

Lights (only used for the realtime reflections) are also exported with datasmith/Unreal Studio. They need some tweaking in unreal but are pretty good.
For complex reflections, I render cube maps in 3ds max/Corona and use these in Unreal reflection probes. They are lightweight and don't need lights to be exported.


Of course, this is a temporary workflow until we all bake fast lightmaps/fields in Unreal using Corona Render for Unreal :D

[Fluss]

Of course, this is a temporary workflow until we all bake fast lightmaps/fields in Unreal using Corona Render for Unreal :D

Don't expect that, Vray just took the seat

[Jacolath]

Thanks for the replies.

@maru thanks I am already using Datasmith. The only reason i would go into Unreal at all (for now) is to have the functionality of generating several images of a space quick. I am not using the interactive output yet because I feel the end user (people who buys condos and hosues etc) can not interact with the media that well yet (wasd with mouse and keyboard or tethered to a HTC Vive). I'm sure this will change in the future but for now gearVR with stereoscopic panoramics from Corona in a tour suffices + the quality is far better than UE (very succesful at launch events etc). It is specifically for generating lots of perspectives fast with Corona render quality that I was interested in this idea.

@Ondra Thanks for the explanation. I realised that this was similar to what we did in the old days with rendering animations in VR with precomped light Cache + Irridiance and also UHD Cache with Corona animations. I think my misunderstanding could be that I was under the impression one could separate the GI from the Path tracing pass out from things like reflections/refractions and only deal with the latter in render pass which in my mind would make things fast. But I dont actually know about this in depth so I'll take your word for it ;)

@romullus funnilly enough I have actually been looking around to see if there are any 3D lightfield renderers out there. Corona level rendering with 6DOF in VR would be great although I think playback might be an issue :)

@rambambulli I have thought about this for realtime web based playback. but for the specific purposes of generating a lot of renders that seems like a lot of work and in that case I might as well just do more renders with Corona. Its not that slow :D

Thanks

[romullus]

Did you see latest Octane presentation videos? They talk about lightfield rendering quite loud.

[Jacolath]

yes I did see that. In principle it seems simple to render out the lightfield. I think the difficulties come in with how to store it and play it back. It seems like a lot of information to process in real time. I did not read too far though maybe its explained somewhere.

[Naxos]

This is a plus from Maxwell render (where i come from) : render to texture is working with Corona, as Vray and some others.