Shaders - Specular?

Someone once said that the specular needs to be in the alpha of the color texture. How do you do that?

I thought the specular is a separate map. What happens if you’re using the alpha for some transparency, but you’d also like to use a specular as well?

I’m trying to understand how specular works in Unity. In ShiVa it’s a separate map in which you add…

Thanks!

Put it in the alpha channel of the texture, using Photoshop or whatever.

You could make a shader that uses a separate map for specular. Normally it’s more convenient to have all 4 channels in one texture, but if you need 5 channels, then you need more than one texture.

–Eric

If you have a separate map for the specular (gray scale), how do you bring that into the color texture’s alpha using Photoshop?

And say I have a color map, how do you begin to create the specular in Photshop? I know that program really well, but this is baffling me…

Copy and paste, I would say.

Make an alpha channel for the specular, and then do whatever you usually do.

–Eric

For Unity’s built-in shaders, you have two options:

Specular, where the alpha channel of the texture defines the shininess, and Transparent/Specular, where the alpha channel defines both shininess and transparency. Obviously, this means trouble if you want an opaque part that is not shiny, or a faded part that is very shiny.

I recommend asking in the Shaderlab forum about creating a shader that lets you supply two different channels.