Switch Lumen to NonLumen at runtime

Development Rendering
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1

Is it possible to switch rendering settings at runtime?

Such as switching Lumen to NonLumen at runtime.

Here is an example.

For High Performance PC users, Lumen is ON.

For Low Performance PC users, Lumen is OFF and other rendering settings are adapted.

2

Yes you can do this, either via postprocess settings or just using console commands.

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3

And those console commands are?

I can’t find anything about console commands for lumen.

4

If you type r.Lumen, you’ll get a bunch of suggestions. I believe what you’re looking for is r.Lumen.DiffuseIndirect.Allow ?

5

This turns lumen reflections off but I still can’t enable ScreenSpaceReflections.

r.ReflectionMethod is just ignored

6

It’s:

r.DynamicGlobalIlluminationMethod
0 - None. Global Illumination can be baked into Lightmaps but no technique will be used for Dynamic Global Illumination.
1 - Lumen. Use Lumen Global Illumination for all lights, emissive materials casting light and SkyLight Occlusion. Requires 'Generate Mesh Distance Fields' enabled for Software Ray Tracing and 'Support Hardware Ray Tracing' enabled for Hardware Ray Tracing.
2 - SSGI. Standalone Screen Space Global Illumination. Low cost, but limited by screen space information.
3 - RTGI. Ray Traced Global Illumination technique. Deprecated, use Lumen Global Illumination instead.
4 - Plugin. Use a plugin for Global Illumination.


r.ReflectionMethod
0 - None. Reflections can come from placed Reflection Captures, Planar Reflections and Skylight but no global reflection method will be used.
1 - Lumen. Use Lumen Reflections, which supports Screen / Software / Hardware Ray Tracing together and integrates with Lumen Global Illumination for rough reflections and Global Illumination seen in reflections.
2 - SSR. Standalone Screen Space Reflections. Low cost, but limited by screen space information.
3 - RT Reflections. Ray Traced Reflections technique. Deprecated, use Lumen Reflections instead.

Also, note, that scalability has to be high or epic in order for those to have effect. If you have illumination scalability at low, executing r.DynamicGlobalIlluminationMethod 1 won’t have any effect: it might switch global illumination system from None to Lumen, technically, but you won’t see any difference and there won’t be any performance impact either. But once you also switch the sg.GlobalIlluminationQuality to 2 or 3, then it will work. Same for the reflections, sg.ReflectionQuality should be 2 or 3.

Generate consolehelp.html in the editor, then you can search all console commands available to you in the generated .html file.

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7

Yes. This Cvar command will turn Lumen GI on or off.
1# r.Lumen.DiffuseIndirect.HalfRes=1
2# r.Lumen.ScreenProbeGather.ScreenSpaceBentNormal=0
3# r.Lumen.DiffuseIndirect.SSAO=1
4# r.Lumen.DiffuseIndirect.TemporalAccumulation=0 (May show more noise and flickering)

Or/and r.DynamicGlobalIlluminationMethod=2

Test these and see if that can help to get better performance without turning GI off completely. But to just turn it off then use r.Lumen.DiffuseIndirect.Allow=0

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