Lit vs UnLit : why displaying the specular channel?

Hi,

I sometimes switch to the Unlit mode to check the saturation of my diffuse texture, as I was doing in UDK, to see how it behaves with and without lighting. For an artist it’s a very important matter, therefore, I don’t understand why the Unlit mode displays on top of the diffuse color a sort of overlay of the Specular channel of the material.

This false the render of the diffuse color and doesn’t seem very right. Since the unlit mode is without lighting, I don’t see the point about displaying the Specular. Especially when we have the GBuffer with the Specular channel displayable alone.

Or maybe it’s a bug ?

Hey Fabrice,

Thanks for noticing this. I put it in for the team to look at.

Best Regards,

Ryan

This is intentional. Unlit mode shows how much light materials reflect if they were lit. That means diffuse+specular. This behavior is important to get a sense of the material colors and brightness for your scene when metals are used. If you want to see what individual material outputs look like, use the Visualize Buffer viewmode.

Hey Fabrice,

Could you provide some pictures of this and possible the material?

Best Regards,
Ryan

Regarding the material, nothing fancy, just some textures plugged in the right input. However, it’s a material using a subsurface lighting model.

Screenshot :

spec_unlit.gif

I can confirm this also happens with regular materials with the default lighting model (without textures this time, just constants).