RT-Viz questions


I’m not even an Arch Viz noob, I have never entered this field but I’ve got a couple questions from you guys.

A) When it’s said “Real Time Arch Viz”, is it referred only to the interactive environment or it means the lighting is all dynamic too?

B) Is it possible to get realistic results like you viz guys do but with use of only dynamic lighting? I know that it’s not going to look as good as when you build lighting but I’m curious if anyone has managed to get very good results using only dynamic lighting. Is anyone around here doing it?

A) It means that you can explore your scene and do stuff on the fly (screenshot, movie) because the rendering is done on the fly, 30, 60 or even more time per seconds.

B) Not really unless it’s just an exterior shot. For an interior it will never look really good because there is no dynamic G.I solution good enough for architecture needs! The closest is VXGI but it’s still not enough for interior imo.

Koola have made some cool exterior shots with movable sun/sky. Especially his winter scene demo. It looks stunning and it’s all dynamic…but add a building with an interior and you are screwed. Might be fine for shots of the exterior, in an overcast day, without to many shadows, but still isn’t ideal. You won’t get contact and soft shadows with dynamic sun/sky, that’s the problem.

Alright thanks.

Is Koola the only one around here who managed to create realistic exteriors with only dynamic lighting? Anyone else?

Not ArchViz, but the Kite Demo from Epic is a pretty great dynamic scene.

Koola’s work is mostly short exterior tech demo movies…not really architecture viz so to speak. His work is outstanding tho!

Kite Demo looks great but by looking at it you could easily tell it’s very far from real life but Koola’s exterior’s rendered using real time lighting is a lot more close to real life. Kind of confused what he does with his simple real time lighting setup that makes his scenes look absolutely realistic.

For realistic Exterior; I found this thread
VXGI firsts test for arch viz!

For realistic Interior; I had just found this one
Archinterior conversion (Evermotion) + VXGI tests

The 1st one is my thread. I abandoned the idea of doing arch-viz with vxgi for now. It’s too restricting.

Koola scenes are dynamic because they’re small, and he carefully chooses the plans he wants to show. It’s not viable in a full scale arch-viz project when you have rooms full of objects and stuff! It’s just good for minimalist stuff.

VXGI should work OK, not as good as baked lighting, but you can turn up the number of voxels to get better lighting detail if you have a powerful machine. And if you’re just doing animations then you can turn it up and not care about performance much.

For PC games though, what are the optimal settings for VXGI?

Edit: Thank you all for the replies and links. :slight_smile:

AFAIK there are no games using it yet. It’s a feature still in alpha stage, there is pretty much no documentation about it. It’s kinda heavy and if you make an arch-viz with it, your client is going to need a beast of a pc. I suggest you try something else. What kind of project are you trying to do exactly?

^ Doing tests for an open world game.

Not sure why the environment is lit all the way. Everything defaults + Multi-Bounce enabled.

For a game and open world it could work because you don’t need that much finesse in your shadows!!!

I went through a thing with some people about lighting issues with VXGI and after a bit, it surmounted to no solution (viable anyway), but if you’re set on using it, I have some tips (they may not apply to you).

Directional lights are heavy on the lighting-errors and you’d be best to completely avoid VXGI in it.
Spotlights/Pointlights generally work well enough but if you want less light leak in “them” (not directional, I said avoid that) you could increase the sampling thing in the VXGI Post Processing (I forgot what it’s called but I think it’s default at 2 and higher values decrease performance).

If you run into any light leaks (and your wall isn’t just like paper-thin), you can set the external faces material to black or [not]-use-VXGI. (this fixes the problem but is impractical because it disables what you probably want in the first place)

This+SVOGI+lack of FishEyeLensDistortion (<< mostly this) is why I give up on UE4 in favor of Unity5 for now.
I mean I know I have to compromise somewhere in graphics but I’d rather it not be at dynamic lighting. UE4 has better navigation and things are easier to setup in it, plus the post processing is better (and by default, all the default graphics are generally better) but Unity5 is easier to load files and has dynamic lighting (some anyway).

Note: If you’re reputable (or something like that, the conditions are hidden) then you could use enlighten with UE4 for dynamic lights.
P.S. Seriously, Fish-Eye-Lens is a big deal for me o_o

I see directional light has troubles with it. I just tried a spot light it it gives much more smoother and accurate results. Why not using a spot light as the sun?

To light an interior with spotlight ok but for exterior it’s not going to work because of spotlight’s limited radius.

By dragging it’s slider to the right side the maximum radius is 16384.0 but I just tried inputting numbers higher than that and it works. :slight_smile:

It looks like the voxel size or whatever it’s called is too low. Basically everything gets converted to voxels to make things simpler, the smaller the voxels the better quality you get but it makes it slower. It looks to me like the voxel size in your scene has like 3 voxels covering the whole room.

how do you adjust the voxels?

@darthviper107, Yeah took some time to play with all the parameters. At 32 cones it gives acceptable results. I had 4 in image above.

When creating a new level with just a floor I’m getting ~3.6 ms. How many ms(s) is wise to add to this time to have vxgi?