Vray for Unreal Engine

[francomanko]

Any chance you can slip in a quick chat to Epic about how to do support like chaosgroup, because frankly unreals is awful. I've just started using it, and the most frustrating part is having to rely on 'unreal answers' which is just the worst way to go about it.

[vlado]

Any chance you can slip in a quick chat to Epic about how to do support like chaosgroup, because frankly unreals is awful. I've just started using it, and the most frustrating part is having to rely on 'unreal answers' which is just the worst way to go about it.

It's really a rude way to answer, but I guess you get what you pay for Jokes aside though, I suppose Unreal has so many more users that it's not practically possible to pay attention to everyone.

Best regards,
Vlado

[duke2]

Is there any way we can get in on testing this? We're using Unreal every day now for viz and would love to integrate VRay.

[samuel_bubat]

This is the never ending feud, unreal vs unity!

I've been using Unity for arch viz previz since the first Oculus headset came out...
But I think people choose Unreal because they think the lighting/gi looks more realistic. I've been baking my lighting from Vray from the beginning so it never appealed to me. At least for me, Unity was easier to drop an FBX in and then drop into a Unity scene - and also easy to update/replace FBX files automatically. Maybe Unreal has improved - and if Vray is coming to Unreal first, I'll have to switch over and check it out.

Just talking about baking. It's probabely a similar discussion like the "Corona magically makes better renderings than Vray" discussion. I don't know Unity good enough to judge. About the Unreal baking i can say. You can get pretty good results. But the way to get there is simply a pain. I spend days of tweaking non exposed parameters in the ini files to get a decent GI quality. Attached is an image that shows, for a game engine, reasonable sharp indirect shadows. But light calculations in Unreal also do more than just baking a texture. For some reason it also bakes some sort of light direction normal map. Not yet sure what they are beeing used for. Also an light volume is created that is used to ambient light dynamic objects so they fit visually into a baked scene. This is pretty nice.

In my opinion Vray should aim to become a baking replacement for lightmass. It's great and important to get a quick preview in the editor. But after that you want to have this quality in your final project as well. Going the Otoy Brigade way is probabely to early or just interesting for a very few companies who can provide the neccessary render power.

Why lightmass sucks. As I said you can get decent results but the way to get there is the problem. You can compare the engine itself a bit to Mental Ray or even Vray. It consists of two steps (secondary primary GI). A traditional photon mapping. And some sort of final gathering or irradiance mapping. Unlike lightcache the photon mapping is not very optimised. It doesn't support skylight and the resolution is very low without tweaking the ini. It causes a lot of light bleeding but it's pretty fast to calculate. On top of that comes the final gathering wich is not that bad but very very slow to calculate. Lightmaps are not accessible per object. At least not for a normal user. Several objects may be merged into one lightmap. So there is no way to bring in your own lightmap.You'll need to bring them in by material. The calculation is the biggest problem. Distributed rendering exists but it calculates one lightmap per thread. So no matter how many threads you have, in the end you will always have a handfull of threads running forever while all the other machine are idle. You can't calculate single objects or just parts of the scene. This makes Lightmass very unflexible. Memory mangement: You are limited to a certain lightmap size that may differ depending on the Memory but also on the size of lightmaps each thread grabs to render. I often had to hard restart my workstation. On a second attempt it worked. But in general this problem often prevents lightmap sizes your GPU could easily handle because the calculation process crashes your machine. Render times. the attached images are from a scene with three rooms. With my lightmass settings on all our machines it took roughly 24 hours. Vray would have done this in a fracture of time and better quality.

This is why I think Vray as baking engine for Unreal would not only attract archvis, automotive or product people. It' s also very interesting for game companies. Why not rely on a render engine that is affordable, faster, more flexible an produces a better quality while it doesn't affect ingame performance.

[cheerioboy]

Just talking about baking. It's probabely a similar discussion like the "Corona magically makes better renderings than Vray" discussion. I don't know Unity good enough to judge. About the Unreal baking i can say. You can get pretty good results. But the way to get there is simply a pain. I spend days of tweaking non exposed parameters in the ini files to get a decent GI quality. Attached is an image that shows, for a game engine, reasonable sharp indirect shadows. But light calculations in Unreal also do more than just baking a texture. For some reason it also bakes some sort of light direction normal map. Not yet sure what they are beeing used for. Also an light volume is created that is used to ambient light dynamic objects so they fit visually into a baked scene. This is pretty nice.

In my opinion Vray should aim to become a baking replacement for lightmass. It's great and important to get a quick preview in the editor. But after that you want to have this quality in your final project as well. Going the Otoy Brigade way is probabely to early or just interesting for a very few companies who can provide the neccessary render power.

Why lightmass sucks. As I said you can get decent results but the way to get there is the problem. You can compare the engine itself a bit to Mental Ray or even Vray. It consists of two steps (secondary primary GI). A traditional photon mapping. And some sort of final gathering or irradiance mapping. Unlike lightcache the photon mapping is not very optimised. It doesn't support skylight and the resolution is very low without tweaking the ini. It causes a lot of light bleeding but it's pretty fast to calculate. On top of that comes the final gathering wich is not that bad but very very slow to calculate. Lightmaps are not accessible per object. At least not for a normal user. Several objects may be merged into one lightmap. So there is no way to bring in your own lightmap.You'll need to bring them in by material. The calculation is the biggest problem. Distributed rendering exists but it calculates one lightmap per thread. So no matter how many threads you have, in the end you will always have a handfull of threads running forever while all the other machine are idle. You can't calculate single objects or just parts of the scene. This makes Lightmass very unflexible. Memory mangement: You are limited to a certain lightmap size that may differ depending on the Memory but also on the size of lightmaps each thread grabs to render. I often had to hard restart my workstation. On a second attempt it worked. But in general this problem often prevents lightmap sizes your GPU could easily handle because the calculation process crashes your machine. Render times. the attached images are from a scene with three rooms. With my lightmass settings on all our machines it took roughly 24 hours. Vray would have done this in a fracture of time and better quality.

This is why I think Vray as baking engine for Unreal would not only attract archvis, automotive or product people. It' s also very interesting for game companies. Why not rely on a render engine that is affordable, faster, more flexible an produces a better quality while it doesn't affect ingame performance.

I didn't mean to say I was using Unity to bake the lighting. I've been using Vray all this time for my light baking. I find Unity to be easier than Unreal to simply drop the 3d model and baked texture into a project and get it up and running quickly. And also iterate off the initial model quickly as well.

Honestly if Vray replaced Lightmass and/or whatever Unity uses - I'm not sure if I'd like it. I much prefer doing my baking in 3dsmax/Maya where I can use DR and network rendering and also preview each baked map as it renders to watch for any issues. I really don't like how the game engines do it where you're sitting there for a half hour or longer just to find issues and need to tweak again. But I welcome any advancements in baking lighting into geometry. I've always really really hated 360 rendering. I see companies trying to capitalize on it and it looks like a huge gimmick. There's no sense of scale or presence in a 360 rendering.

[duke2]

I didn't mean to say I was using Unity to bake the lighting. I've been using Vray all this time for my light baking. I find Unity to be easier than Unreal to simply drop the 3d model and baked texture into a project and get it up and running quickly. And also iterate off the initial model quickly as well.

Honestly if Vray replaced Lightmass and/or whatever Unity uses - I'm not sure if I'd like it. I much prefer doing my baking in 3dsmax/Maya where I can use DR and network rendering and also preview each baked map as it renders to watch for any issues. I really don't like how the game engines do it where you're sitting there for a half hour or longer just to find issues and need to tweak again. But I welcome any advancements in baking lighting into geometry. I've always really really hated 360 rendering. I see companies trying to capitalize on it and it looks like a huge gimmick. There's no sense of scale or presence in a 360 rendering.

The announcement/slides say you can do a preview render, which is better than what we have now - you can see what you'll get before you bake. And there's no reason to think that this integration won't have a VFB and DR like VRay "proper".

[Oleg_Budeanu]

I didn't mean to say I was using Unity to bake the lighting. I've been using Vray all this time for my light baking. I find Unity to be easier than Unreal to simply drop the 3d model and baked texture into a project and get it up and running quickly. And also iterate off the initial model quickly as well.

Honestly if Vray replaced Lightmass and/or whatever Unity uses - I'm not sure if I'd like it. I much prefer doing my baking in 3dsmax/Maya where I can use DR and network rendering and also preview each baked map as it renders to watch for any issues. I really don't like how the game engines do it where you're sitting there for a half hour or longer just to find issues and need to tweak again. But I welcome any advancements in baking lighting into geometry. I've always really really hated 360 rendering. I see companies trying to capitalize on it and it looks like a huge gimmick. There's no sense of scale or presence in a 360 rendering.

Well in Unreal you can use Swarm as distributed - quite easy to do. Talking about Unreal it is really quite a pain to control LightMass settings via INI files without any documentation and explanation - and there is a lot of parameters!
I understand that process of integrating VRay as a main baking solution for Unreal is not that easy as it sounds, but it would be a miracle to have such power in Unreal.

[vlado]

I figured it out. It' s not the browser. It ' s a char on a german keyboard that seem not to be supported by the forum. It' s bad habit of me not to use the intended " ' " char but another one that probabely only exists on a german keyboard. The key left to the backspace key.
http://www.kachold.de/images/tast_d.gif

This should be fixed now.

Best regards,
Vlado

[Syclone1]

If I had V-Ray available and could use it for the Unreal engine as well as render out frames that would be beyond awesome for me. We are currently using Unity for the training simulators that I build but would be all over Unreal if V-Ray was more integrated.

[francomanko]

Well in Unreal you can use Swarm as distributed - quite easy to do.

I never had much success with swarm, it never used all my farm, always dropped one...were there any setup tips/issues you found and resolved?

[Oleg_Budeanu]

I never had much success with swarm, it never used all my farm, always dropped one...were there any setup tips/issues you found and resolved?

To be honest no issues at all. The only thing was that i had a machine with 72 cores and Swarm did not use all of them. So i've found a solution for that on forums - there was a setting to change.

[duke2]

To be honest no issues at all. The only thing was that i had a machine with 72 cores and Swarm did not use all of them. So i've found a solution for that on forums - there was a setting to change.

And what setting was that?

[Oleg_Budeanu]

And what setting was that?

Enable the developer options( by setting the developer options to true) & set local jobs default processor count to the number of processors to use.
Don't forget that multiple cores can't write to one lightmap texture at once, so there can be times when some cores are waiting for others to finish before they can move on (this is why you usually end up with just one core working at the end of a big build).

[Macker]

So is the suggestion here that chaos group are creating some kind of "importer" for lack of better words that will enable me to take my scene from 3DS Max (with VRay materials and lights) into Unreal engine with only a few clicks, or have I missed the point entirely, or is it too early to say?

[raistlin]

Ok, so we couldn't have official news, but... i'm thinking about new workstation, and i really could find pretty smart to know if i've to perform CPU or GPU on my budget...
thanks Vlado, because last year i've bought 4 dual xeon CPU Blades with 64 Go ram... And it should be a dramatic choice if i buy the same thing and if Vray follow GPU way...
Please... just let me know, in private or here...