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Vam 2 Realtime GI

kinski

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More of a question than a suggestion at this time:

What realtime GI will VAM 2 support?

SSGI? APV (adaptive probe volume...which would require some baking per scene)?

Lack of "proper" GI is one of the larger shortcomings of VAM imho. So what can we expect for VAM 2?
 
I suppose in VAM 2 we will see all features that are available in latest Unity. So I hope we will get a good GI.

Currently there are only screen space ray tracing options for VAM
- RTGI Pascal Gilcher's ReShade screen space ray tracing
- NVIDIA's RTXGI
 
I suppose in VAM 2 we will see all features that are available in latest Unity. So I hope we will get a good GI.

Currently there are only screen space ray tracing options for VAM
- RTGI Pascal Gilcher's ReShade screen space ray tracing
- NVIDIA's RTXGI
I'm not sure we'll see al available features. APV for example requires baking and while it works for dynamic objects, it does not work with dynamic (moving) lights. So not necessarily ideal for VAM (especially the baking). I was hoping that there is maybe some Raytracing middleware that could be used for GI. Since VAM scenes tend to be microscopic in geometric scene complexity, the BVH should be simple and therefore the performance impact comparatively (!) small.
Perhaps a decent SSGI (screen space) solution would be good enough... but i'm not sure if unity has native support for SSGI... do you know?

I did not know that there is screen space "raytracing" vor VAM. Does it work well? I could not find it on the HUB... can you provide a link?
 
I did not know that there is screen space "raytracing" vor VAM. Does it work well? I could not find it on the HUB... can you provide a link?
So-so, because it is "screen space". Besides I couldn't run it in VR

All official info

Start with VaM2 Alpha3 Discord Channel FAQ

"Conversion from 22.3 to Unity 6 should generally be very straightforward. For environments, you are likely going to want to use Unity 6's Adaptive Probe Volumes (APV) which make global illumination a lot easier. So if you are going to start making environments for 2022.3 and use light probes, just keep in mind you may have to redo all of that work to upgrade to APV."
 
So-so, because it is "screen space". Besides I couldn't run it in VR

All official info

Start with VaM2 Alpha3 Discord Channel FAQ

"Conversion from 22.3 to Unity 6 should generally be very straightforward. For environments, you are likely going to want to use Unity 6's Adaptive Probe Volumes (APV) which make global illumination a lot easier. So if you are going to start making environments for 2022.3 and use light probes, just keep in mind you may have to redo all of that work to upgrade to APV."
thx!
 
I could not find it on the HUB... can you provide a link?
NVIDIA

RTGI

RTGI was not free. I am not sure about the current status. Let me know if you find out.
 
VaM2 will support APV as the realtime GI solution. It is the best overall solution for working across desktop and VR. It is also the easiest for scene creators to use. The addon kit also supports creating scenes with baked or mixed lighting. APV doesn't really require baking, but you do have to set up the probes in the scene (in Unity), and they are fixed in place.
 
APV works with both moving objects and moving lights. You can't move the probes at runtime though.
Hmm...it looks like I might be wrong on this, but I swear with my early testing with APV that moving lights correctly worked with bounced (indirect) lighting.
 
APV works with both moving objects and moving lights. You can't move the probes at runtime though.
thanks for the replies. if APV supports moving lights, that's great. the demos never showed it, so i was just assuming this was a limitation.

from the demos i've seen APV looks quite good. perhaps comparable even to raytracing... what are the limitations then? i assume less precision and potential for light leak (from probe misalignment)?

do you foresee any possibility for the light probes to be generated without addon kit directly in VAM 2?

if that cannot be achieved, how well do you think APV would hold up when the scene would be "heavily" modified within VAM?
example: my own scenes are mostly just variations of a floor and two walls that i prop up with objects and interesting light setups to create interesting visuals.
let's say you would ship VAM 2 with some variation of those very simple scenes (just a floor and 2 walls with probes in place). could users (without addon kit) then modify the scene in VAM 2 (change textures, add props, maybe add walls... a ceiling...) or would APV struggle if too much is changed?

if such a workflow was somewhat possible, i would be very happy. i think i'd be savvy enough to use addon kit (i'm very familiar with blender and other programs), but for me a lot of fun in VAM comes from building those scenes (and light setups!) in a playful realtime environment.
if i could keep doing that in VAM 2, but with the added benefit of APV powered realtime GI that would be a dream!
 
Hmm...it looks like I might be wrong on this, but I swear with my early testing with APV that moving lights correctly worked with bounced (indirect) lighting.
i could be wrong too. the official demos just never showed it and i know too little about the technical background to make an educated guess.
i do know that there are probe based GI systems that support moving lights, i just don't know if APV is one of them.
 
OK - weird. I have a test scene in the current VaM2 addon kit using the older light probe group system, and moving dynamic lights at runtime does work correctly with bounce (indirect) lighting. As I move the dynamic light around it does correctly cast bounce lighting from a static object onto another dynamic object. This bounce lighting is calculated from the probes. APV is built around light probes, so I would assume it would also work in this setup. I don't currently have a project with APV set up so I won't know for sure until I test that further, but the fact that it works with light probes suggests to me it will also work with APV. The documentation is not clear on this at all.
 
OK - weird. I have a test scene in the current VaM2 addon kit using the older light probe group system, and moving dynamic lights at runtime does work correctly with bounce (indirect) lighting. As I move the dynamic light around it does correctly cast bounce lighting from a static object onto another dynamic object. This bounce lighting is calculated from the probes. APV is built around light probes, so I would assume it would also work in this setup. I don't currently have a project with APV set up so I won't know for sure until I test that further, but the fact that it works with light probes suggests to me it will also work with APV. The documentation is not clear on this at all.

the existence of "lighting scenarios" seems to indicate that dynamic lights are not supported. from my understanding you'd bake multiple variations with different states for light sources and unity can then blend between them. useful for lights turning on/off or moving between pre-planned positions (f.e. rotating beacon).
i think for VAM purposes that's not "dynamic" enough unless lighting scenarios could be updated ("baked") in VAM itself.
 
Here is an example of it working (with older light probes). The blue cube is static and contributes GI to the scene (as you can see on the static gray floor which is tinted a bit blue under the cube). The gray cube is dynamic and can move around. The white sphere is a dynamic light that can move around. In 1st image the backside of the blue cube is not receiving any light so does not bounce blue light. In the 2nd image the backside of the blue cube is lit by the dynamic white sphere light and does generate blue bounce light as can be seen on the gray cube. With the dynamic light turned off, the scene is completely black.

1735919848993.png


1735919862296.png


So at least for older light probes, this scenario works. My understanding is APV uses probes and didn't change support for this scenario. I'll find out soon enough when I move the addon kit to Unity 6 and update this test scene. APV should look even better since it calculates per pixel instead of per vertex. I can report back here after I update. This scene is included in the VaM2 addon kit as an example.
 
OK - it looks like the older Enlighten realtime GI solution supports dynamically moving lights, but the new APV system does not. Enlighten is still supported in Unity 6, so technically VaM2 scenes could be made that use it. I'll still report back after I update the project to Unity 6 as I would like to support the above scenario with dynamically moving and changing lights producing bounce lighting. Perhaps there is a way to support both scene styles in VaM2 and the scene creator can decide.
 
[...] the older Enlighten realtime GI solution supports dynamically moving lights, but the new APV system does not. [...]
Perhaps there is a way to support both scene styles in VaM2 and the scene creator can decide.
I see. Well at least i'm happy that you're on it and that we'll get some form of realtime GI.

My only wish then would be to have as much functionality as technically possible in VAM itself (without addon kit) so that users can modify scenes and lighting in VAM without loosing realtime GI.
 
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OK - it looks like the older Enlighten realtime GI solution supports dynamically moving lights, but the new APV system does not...
Maybe you could look into a way for the APV probes to be updated in VAM itself (re-bake). No need to add new probes or change location of probes, but for users it would be a very important feature to add lights in the scene without addon kit. With APV this would need a quick re-bake. I hope this can be enabled in VAM.
I think i'm not the only one who uses VAM as a lighting visualizer and sandbox...

Alternatively consider raytraced GI. I think currently it's not fast enough in Unity, but future updates might improve it. Also VAM scenes should be easy on the BVH structure and if it's only about GI (and not reflections, schadows, etc.) you could use a very simplistic representation for the models (no need to have morphs, complex hair and physics represented in the BVH).
It should be comparatively fast, if there aren't additional bottlenecks in the unity pipeline...
 
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NVIDIA

RTGI

RTGI was not free. I am not sure about the current status. Let me know if you find out.

Don't get me wrong, I do wanna try out the Nvidia SSRTGI filter, but these are all just filters. It can make images more natural and realistic, but at the end of they day, those are still filters. But it's still better than nothing.

I would rather see a good lighting system like mentioned above like NVIDIA's RTXGI, RTXDI or maybe even ReSTiR and ReSTIR GI. But the problem with this is, that you limit your software only for mid to high range GPU's and i'm talking about minimum RTX 3070 to RTX 4090 or AMD aquivalent cards.
 
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OK - it looks like the older Enlighten realtime GI solution supports dynamically moving lights, but the new APV system does not. Enlighten is still supported in Unity 6, so technically VaM2 scenes could be made that use it. I'll still report back after I update the project to Unity 6 as I would like to support the above scenario with dynamically moving and changing lights producing bounce lighting. Perhaps there is a way to support both scene styles in VaM2 and the scene creator can decide.
I'm looking forward to. Bouncing light gives so much more depth and natural feeling to scene's.
 
[...] It can make images more natural and realistic, but at the end of they day, those are still filters. But it's still better than nothing. [...]
What's that supposed to mean? Filter or not; isn't that just semantics?
 
@meshedvr after having watched the NVIDIA keynotes and having seen rumors about upcoming AMD GPU RT performance i think it might really be worth thinking about ditching probe based GI and exclusively going RTGI for VAM 2 depending on planned release date. If VAM 2 releases in 2026 or later even low end cards will be able to run it with RTGI by then.

Refelctions and shadows could still be done in raster to weaken the burden on budget GPUs...
 
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