Spec map issue

ozzy310

Hey, polycount

I got a question and it could possibly have a simple answer, I noticed when applying a spec map to a model it does not appear to display any highlights when using an ambient light under high quality only with other source of lights. Could just using an ambient light make the spec map ineffective?

I have been using blinn, phong and have been messing with the levels.

Eric Chadwick

Ambient shouldn't prevent highlights. Are the lights making specular highlights when the Texture is removed?

A screenshot of your spec settings, and the lit model, would help immensely.

kodde

What is your software and shading context?

Xazas

Difficult to tell without knowing what you are rendering with but "ambient" light normally means a light that is all around and does not have a specific source location or direction. Specular highlights are a directional reflection of your lightsource and therefor wont work with just ambient lighting because ambient lights do not have a source in a geometrical sense.

Obscura

Yeah... Without IBL, you won't get specular from ambient light, because of what Xazas said. It doesn't have direction or position. The thing is a bit different with IBL, then you can have highlights in the ambient lighting, but actually that still not a "specular highlight" in the result, and it affects only the diffuse. Specular reflection need light source, or specular IBL.

ozzy310

I’m using Maya and plugged in the spec map in specular color. The model is a simple oil drum that I use to test things out, the spec map I made has a strong highlight so it can stand out when interacting with a source of light. I know that ambient light is used as a background light and usually you combine it with other source of lights to have dynamic lighting. I always assumed whether using normal maps or spec maps it would still interact with ambient lighting.

Eric Chadwick- I still get the same result with or without the diffuse map applied to the model.

Joopson

Yes, that's the function of an ambient light. To provide nice even shading from all angles, without any specular highlights. Think of it a bit like a sphere surrounding your model with light coming from all directions equally.

So you'll need another type of light if you want the specular highlights to be evident.

ozzy310

I thought it might be that but I was in doubt, I thought there was a chance I overlooked something. Thank you and everyone else it definitely put my doubts to rest.