Hey, I’m having some trouble matching the results I get in Unreal Engine with the results I can achieve in Marmoset Toolbag using a PBR workflow with metalness and I’m hoping someone can provide some tips and tricks.
What is confusing me is how to set up a HDR scene where I can preview my meshes in correct lighting.
Right now I have a backdrop sphere with a texture applied to it. I also have a skylight with the same but more low-res HDR texture applied to it to get the correct lighting from the scene, the skylight is set to SLS Specified Cubemap and is using the HDR texture as a “cubemap”.
I also placed a directional light in the scene. I would like to not do this, but without it I don’t seem to get any “specular” highlights so to speak. If I turn it off and only use the skylight with the HDR the shading becomes very flat and boring.
Worth mentioning is that I haven’t baked the lighting for these meshes as they are weapons and should be dynamically lit, the Skylight is set to “stationary” right now, switching it to static or movable yields different results but I’m not sure any of them are better. I don’t have a UV set for baked lighting on the meshes and right now they are imported as static meshes even though they really should be skeletal meshes or something dynamic in the end.
So with my two lights, what intensity should I use for it to be in the correct range? Right now my directional is set to 0.5 and my skylight is set to 0.5 in intensity. Ideally I should not use the directional at all and only the skylight at 1 intensity I guess?
Does that mean that there’s something wrong with my HDR texture or is it the way I set it up in the scene? Any thoughts would be appreciated.
Another issue, how can I match the rotation of my skydome with the rotation of my HDR cubemap on the skylight? I guess that could also be part of the problem.
Hey, that does sound pretty interesting, I might have a look at your scene for clues should my efforts fail. Though I’m going to give it a few more tries getting this scene I’m working on correctly lit. I need to get an understanding of how everything is connected in Unreal, so any hints are still welcome. Unfortunately it seems information about setting up HDR based scenes is very sketchy in the Unreal documentation.
You dont need a backdrop sphere if you want it for reflections. The mesh gets the reflections from the skylight cubemap(and you should set it to movable if you arent building lights.) Image based lighting will give you ambient lighting rather than specular highlights so you need a directional light. Set the directional light(which would be the sun if your HDR image is an exterior shot) depending on your image, tweak the AO and other stuff via an unbound post process volume and you should be good to go as long as your materials are setup correctly.
Hey again, I found that I had a ReflectionCaptureActor in the scene and that was overriding my skylight cubemap. Turning that off helped somewhat. However setting the skylight to “Stationary” seems to give the best results rather than setting it to “movable” where the shaders become very washed out and with low contrast.
I’d like to be able to have the backdrop image/ sky sphere represent what is in the skylight cubemap since it will help me determine if the materials of the meshes are correct.
What you are suggesting Jacky is basically the set-up I have right now. A skylight for the reflections and a directional light for the specular highlights.
I’m still confused as to how I can match the backdrop sky sphere texture with the hdr cubemap, I had rotation on my sky sphere and setting that to 0 matched the hdr cube better.
Can I connect the HDR cubemap orientation to the skysphere orientation in the shader or a blueprint maybe? I haven’t really found a place where I can change the orientation of the hdr cube other than doing it in the texture.
Another issue is the strength of the skylight, I’m assuming that it should be set to “1” since I want the unaltered light information from the .hdr map. But I don’t know…
You can do this to position the backdrop image same as your cubemap: Place a sphere in the level and give it a chrome material so that you can see the reflections clearly. Then rotate the skysphere until it matches the reflection on the sphere. It wont be perfect but it should be good enough.
On sky light intensity, yeah, you dont need to set it to more than 1.
Unfortunately it seems information about setting up HDR based scenes is very sketchy in the Unreal documentation.