Sky lighting & background color

[mayaalias]

Hello,

I’m new to this.

I have a sky (dome-like) thing in the background and have set up a specific lighting condition for my scene. Still, I wonder if I can let the camera NOT see my sky, and at the same time replace a solid color but without being affected by the lighting, and I can pick any “solid color” I want as a background color.

Any idea?

Thanks

[Simplychenable]

@mayaalias to confirm, you are looking to create a (colored) plate that is visible to the camera but not contributing to the scene’s illumination while turning visibility off on the skydome but letting it still contribite to the environment/ambient lighting, correct?

are you using kit app template/composer or Isaac Sim?

[mayaalias]

Hi,

Thanks for the prompt reply, yes, I wonder to have a “background color” like thing and let me control the BG color at the same time, and yes, I don’t want it to illuminate the others.

Douglas

[mayaalias]

Oh sorry, forget!

I am using Kit

[Richard3D]

Hi there and welcome. What version of kit? USD Composer? Isaac Sim? What version?

The main choice is:
A) render out your scene on a transparent background using an alpha channel, and add the background in post, like photoshop, or after effects
B) add the background now, in camera, in viewport, and render out with the background without an alpha channel, no post required

Personally I would go with A) and just render out on transparent PNGs

[Richard3D]

In the old 2023.2.5, there used to be a Composition option where you can direct a background color and texture, but I do not see it now in kit 107.3. I am investigating. It should be there.

2023.2.5

107.3

[Simplychenable]

@mayaalias to add to what the mod has said, i will attach a few more images since you are new. if you do go with Compositing option you can find the option under Render Settings panel > Post Processing > Compositing

once enabled, you can add the background texture via the Rendering Settings panel > Common > Background.

if you get weird rendering artifacts such as ghosting, you may want to try switching to RTX - Interactive (Ray Tracing) from the default RTX - Real-Time mode to get rid of ghosting issue. you can do so via the viewport display controls.

[Simplychenable]

the third option, perhaps more old-school, is to create a skybox/plate mesh prim (such as a giant plane or sphere that encompasses your scene) in your DCC or directly in Kit so you can have control over rotational values. For example, if you have a spherical HDR that you wish to use as a sky plate, you can create a OmniEmissive material (with Backface Emission enabled) and assign it to a giant sphere; that will allow you to rotate the sphere itself to desired angle for the camera. If you do approach it with this method, you will want to disable Cast Shadows and enable Invisible To Secondary Rays. the former will ensure it doesn’t cast shadows from other scene light sources, such as a DistantLight; the latter will prevent the plate from contributing reflection values to your scene.

overall all, there are a lot of options to choose from and each has their pros and cons.

[Richard3D]

Ah yes. Thanks @Simplychenable I just found that out. We have moved all the “background” to the common tab

[mayaalias]

Oh, thank you so much, I will give it a try.

Douglas

[mayaalias]

Thanks for your help. I’ll see what I can do.

Douglas