Unwrapping a mesh , Is this a mandatory operation ?

Development Rendering
1

I’m planing to use UE for architecture
I saw some tutorial movies recently
and they’re talking about Unwrapping with high fidelity for lighting
plus, you need to put lighting Unwrapped set into second channel
so, to have diffuse at first I guess
but anyway , Can I avoid unwrapping every single model if I’m doing architectural viz ?

using last 4.13.1 UE

Best Regards !

2

For best results, yes you would need to have a UV channel unwrapped to use for lightmaps. The lighting is saved to an image map which is applied like a texture to the mesh, so it has to have UV’s set up properly for that.

3

You can use scripts to auto unwrap on channel 2, using flatten mapping and choosing the spacing of your choice. Of course it’s not as good as manually unwrapping it yourself but it’s more than ok for most objects.
Check this project I did… I use auto unwrap on everything and the shadows looks good, no artifacts. https://www.behance.net/gallery/40708729/Real-time-luxury-apartment-scene

If you have a ton of curved objects then it may be a better idea to manually unwrap.

Here’s the script for max http://www.scriptspot.com/3ds-max/scripts/steamroller

4

I’m not a max user (( any scripts like that for maya ?
I saw in tuts people using the scripts because I understand there is no chance to unwrap 10000 models by hand
so, you said curved objects , so lets say I have statue how can I unwrap face body ?
same as I would unwrap for diffuse ? or I don’t understand … how can you left the same distance between gaps if you are unwrapping human body or any organic form ?
thanks for help

5

thanks for links I saw tutorial I’m preparing myself for hard labor with UE,
according to your image I assume you more than a just user and have more info than others
can we anticipate UE5 in 2017 ?
Do you plan to implement any realtime renderer into engine (Brigade or Enlighten for example) ?
As I understand I need to bake light in order to have GI right ? No chance to have realtime GI without baking ?
thanks a lot

6

If you want architectural viz quality GI for an interior scene, you really need to do baked lighting, or try VXGI (which is very limiting, experimental, less documented, and hardware intensive).

The dynamic GI solutions out there are alright for exterior scene where 1-2 light bounces and mediocre shadows are okay, you can definitely get acceptable results for the outside of a house or building. But if you want a room with clean, great looking lighting and shadows, you’ll have to bake.

7

Good lightmapping, and consequently, unwrapping is essential for ArchViz in UE4. Do not think it is hard labour though. Once you get familiar with it, it will become usual routine. For the time being, no realtime solutions can offer you anything remotely as good looking as baked GI.
For your information, Enlighten also relies on precomputed data.
Brigade is running on a fundamentally different approach and it will take a few years before realtime path tracing starts to be used widely.

8

Thanks for clearing up things a little bit , I think for exterior it will be ok if I use VXGI , moreover its Nvidias software and they will do their best as always , VXGI for exteriors and Baking for interior, not a bad idea I think. moreover, I saw VXGIs quality here : https://www.youtube.com/watch?v=cH2_RkfStSk
scene with colonnade at 0:30 is good and acceptable , plus it supports emission , and AO , well it ok in other words
I downloaded 0.9 version of VXGI an hour ago , but there is not familiar exe installer as I was expecting
any manual how to install VXGI on UE ? thanks a lot

9

Agree about Brigade , moreover, considering the OTOYs speed of developing their plugins, I don’t think it will be ready to work before next millennium.

10

I don’t actually work for Epic–just a mod–but I can answer these questions

UE4 will continue to be developed. Something like UE5 is not going to happen any time soon, it’s not even in development.
Englighten has UE4 integration, however you have to license it yourself which is very expensive. Also, it’s not a great solution–it still uses lightmaps, and the dynamic GI is only for movable lights which is very limiting. In my experience it’s also much slower than Lightmass
Part of the reason that it wouldn’t be added to UE4 by default is because of how the engine source is made available. One of the reasons that Epic created UE4 was because for a long time they wanted to make the source of their engine available to users, but UE3 depended on many third-party solutions. Starting from scratch they were able to make the source for UE4 available but that means any new technology that gets integrated has to be part of that.

VXGI is a pretty good dynamic GI solution, but performance isn’t quite there yet, though if you’re just doing renders then it can work fine

11

Please tell me where can I find “VXGI installation guide” on UE4?
Will my GTX TITAN kepler work with VXGI ?
thanks

12

Main thread:

The official version isn’t updated as quickly so this guy does his own update:

VXGI Will work just fine with GTX Titan

13

Seconding this!

14

thanks for links , let me ask you that also
Do I need to unwrap mesh for light if I’m using VXGI ?

15

Nope, no UV mapping. VXGI works by converting the scene to voxels (basically cubes) and then using that to do a simplified GI calculation so it doesn’t depend on the UV’s at all. The downside is speed, and the quality since the voxel size determines how accurate it is but more voxels increases render time.

16

No uvs for light , but uvs for diffuse and other channels of course , understood
I’ve watched video about lightmass inside UE4 , got little confused after that because , I don’t understand: Are lightmass and directional light mapping same ? or those are different light mapping methods ?

17

Lightmass is the lighting renderer, it’s like using Vray to bake lighting. Directional lightmaps allow you to have baked directional data for lights so that it can accurately have stuff like specularity that blends with the rest of the lighting, it’s not something you have to worry about because it’s internally controlled by lightmass. For VXGI it doesn’t use lightmaps, the specularity is dynamic.

18

I didn’t expect such rapid and good support here
Amazing Support ! thank you all