Answered: Albedo/Specular Map Issue

ryanlearas

When I am working in DDO and 3DO the model and materials all look correct however it appears as if the albedo and specular maps are reversed? All of my Albedo maps are mostly black and my specular maps are close to the color that the material is. I realize I can just switch the 2 maps but it doesn't give quite the same result when plugged into Octane Render. Anyone know why this problem might be happening? I attached some images of the maps exactly as they are exported with the Octane preset from Quixel (Top to Bottom: Albedo, Gloss, Specular). The object being textured is brass with some wear on it (if that is of any help). 

*Also curious if albedo and diffuse are used interchangeably in Octane Render?

Billy Lundevall

Hello. The reason it looks like this is because this is a brass material. Metals have little to no diffusion, which menas the diffuse map would be black. They do however directly reflect most incoming light as well as tint it due to absorbing part of the spectrum, making the specular value colored and very bright. The scratches you put on this are also incorrect as scratches on a metal would have the same specular value as the metal itself.

Regards, Billy.

radiancef0rge

I know nothing about Octane however this 

" All of my Albedo maps are mostly black and my specular maps are close to the color that the material is."

Is how metallic materials are correctly represented, with nominal diffuse information and prominent reflection information. 
https://www.marmoset.co/posts/physically-based-rendering-and-you-can-too/

ryanlearas

Hi Billy,

I appreciate the help. How should the scratches look then? would they be a lighter grey within the albedo map and the specular would be just that solid yellowish color? The biggest problem I am having though is that when I plug that into OctaneRender (even Mental Ray for that matter) it renders black with just a little bit of the yellowish reflection. Below I attached the render with that Albedo plugged into the Diffuse setting (given it is in Mental Ray but the results are very similar in Octane) and below that is where the diffuse is just a flat yellowish color.

Radiance - Thank you, that link is very useful!

Billy Lundevall

Scratches in metal would just lead to more metal, so both albedo/diffuse and spec would remain the same. The only reason to add anything on top would be if there was another material present on top of the metal, like dirt for example. Where scratches would be defined would be in gloss/roughness, normal or both.

I use neither mental ray, nor Octane but I know for sure Octane renders specular like anything else. Perhaps there are a specular weight you need to increase to max? Refraction values could also change the reflection, but not to this extent unless they are incredibly inaccurate.