I’m experimenting with indirect lighting and was wondering if it’s possible to completely deactivate it using Lumen. I have a level that only uses a Directional light that illuminates a green panel. The light that this panel reflects is projected onto another nearby object.
I’ve read that to deactivate indirect lighting, you need to set the “Num Indirect Lighting Bounces” option to 0 in the World Settings, but even when I do that, I still see the reflected light. If I set the “Indirect Lighting Intensity” option of the Directional Light to 0, the reflected light seems to have no effect, but when I move the camera so it points at the green panel, I still see a slight green light projected onto the object, as if the camera is acting like a mirror and reflecting the green light. It’s strange because this only happens in the Lit view mode, and not when I switch to Lighting only.
I’m not sure if it’s even possible to deactivate indirect lighting while using Lumen or if there’s something I’m overlooking.
Sorry is this is a nooby question, Im starting with Unreal.
Those are Lightmass settings, they only apply to baked lighting. They do nothing for Lumen.
With Lumen you can reduce the indirect lighting intensity of the light to 0, but this will only work if you disable screen traces. Realistically, if you don’t want indirect lighting you should just disable Lumen.
So if I still want to use Lumen for any reason, but don’t want any indirect light, the only method is to turn off screen traces with the command:
r.Lumen.ScreenProbeGather.ScreenTraces 0
and then go to all individual meshes and turn down to 0 the “Max Lumen Mesh Cards” option?
This is the only way I have been able to obtain any kind of indirect light while using Lumen. I was wondering if there was another method that doesn’t involve adjusting all the meshes individually.
Of course I know that the most reasonable way of obtaining what I want is simply not using Lumen in the project. I am sure that disabling screen traces and Lumen Cards will lead to future issues, but I just wanted to know to what extent it’s possible to modify Lumen in this way.
if you don’t want indirect lighting, you just disable lumen GI in the post process volume. it will still provide lumen reflections. you only get screenspace reflections or they are enforced to full raytraced hit lighting, since there’s no surface cache available for the reflections.
that’s bad advice, imho. unless you want to exclude indirect lighting from a specific light source, it’s better and more performant to just disable lumen gi alltogether. no need to evaluate and compute the surface cache if it’s not used.
if you don’t do that you gotta set the indirect intensity for every lamp in your world. a poopy way. tbh
yes. but you kept pushing the other hacky method. why that? there’s no point doing that. unless you need to filter what does and what does not contribute indirect. also disabling screen traces requires command line input in the game which is a non-standard method.
Because he literally asked me for it after acknowledging my statement that it was better to disable it:
So if I still want to use Lumen for any reason, but don’t want any indirect light, the only method is to turn off screen traces with the command
If anyone here is failing to contribute, it is you, by continuing to post replies ignoring the context of what has already been posted by both myself and the original author posing the question.
