Why does using the cubetexture generated by a cubecamera as an environment map render the 3D model as a dark shiny object?

[Ajay_Mishra]

What am I trying to do?
I have a photo of an empty room of known geometry (floor, walls and ceiling) and the associated camera parameters. I like to add a 3D model with PBR materials into the scene and illuminate it to match the room environment.

What’s the problem?
When I use the cubetexture generated by a cubecamera attached to the 3D model as its environment map, the rendered object appears dark with a bit of reflecting shine. No base color of any material in the model is visible except may the lamp base. See Fig 1 below. Please note I’m using only the environment map and no other light source, and I used threejs dynamic cubemap examples as my guide.

If I add an ambient and directional light source in the scene, the rendering does get better. See here.

What have I done so far to solve the problem?
0) is the generated texture correct? As shown in the figure above, we added a sphere in the scene and mapped the generate cubetexture onto it. The result looks right! If there’s a way to save it on a file and visually examine a texture, please suggest.

1) Maybe it’s not possible to illuminate the object with just the environment map. So I used https://gltf-viewer.donmccurdy.com/ to test it out and I got the following rendering using the footprint court environment. This is pretty well illuminated.

2) The generated cubetexture is a LDR image whereas the footprint court environment is a HDR texture. My understanding is that we should still see faint color with a LDR environment map.

3) increase the envMapIntensity to 10 but that only made the whole rendering shiny but the basic problem of not seeing any color remained. (credit to @thax for suggesting that!)

[Mugen87]

Is it possible for you to demonstrate this issue with a live example? Without seeing your code, it’s not really possible to search for a root cause.

@Ajay_Mishra

I like to add a 3D model with PBR materials into the scene and illuminate it to match the room environment.

Notice that using the result of CubeCamera as the environment map is not ideal in context of PBR materials for two reasons. It’s a LDR map and it’s not pre-filtered with PMREMGenerator. HDR and pre-filtered maps are in some sense mandatory for realistic PBR workflows.

[Ajay_Mishra]

@Mugen87

It’s a LDR map and it’s not pre-filtered with PMREMGenerator . HDR and pre-filtered maps are in some sense mandatory for realistic PBR workflows.

Thanks @Mugen87 for responding! If it’s indeed the LDR and pre-filtering issues, what do you suggest I should do to resolve it? I can try them and report back.

@donmccurdy had suggested to add a live example too but stripping the portion of the app from computer vision and scene interaction modules is proving to be more work than I anticipated. However, if you are interested, I would be happy to walk you through the code on one-on-one basis.

[Ajay_Mishra]

While I’ve still not figured out a way to create HDR cube, I did resolve the overall dimness of rendered objects even after I would use ambient and directional lights and that was due to not setting toneMappingExposure = 2.2 after having set tonemapping to ReinhardToneMapping. You always need to set the exposure to counter the dimness caused by tone mapping.