Force white alpha channel on RenderTexture

Unity Engine
1

Is there a way to always force an all white alpha channel on a render texture?

2

What i need is to fade the texture in an out and for that i need to use a Transparent shader. Using the Transparent/Diffuse shader works fine with the fading, but i dont want the render texture to alpha blend with the background it should just be diffuse.

So come to think of it is it possible to modify the Transparent/Diffuse shader to just overwrite what is in the alpha channel of the texture with the color white. I think that would solve my problem.

I am however new to shader coding and the Transparent/Diffuse shader is rather large.

Hope this clarifies what i really want to do. Any help will be apriciated.

3

It would be much simpler using Transparent/VertexLit shader (and faster as well; I guess you don’t need per-pixel lighting on your fading-out-thing).

Changing the Combine line near the end of the shader into this:

Combine texture * primary DOUBLE, primary

would do the trick. Here I changed “texture * primary” alpha combine operation to just “primary”, so it does not take alpha channel from texture at all, just from the color.

4

Thanks you very much Aras! Works a charm.

Btw i set SeparateSpecular Off aswell as it seems to give to much light on the texture giving it a to white’ish glow.

Thanks again!

5

If you don’t need lighting you could simplify the shader even more.

6

Its for an 3D in-game menu so i do need some light or the texture will seem dark. Atm. i have one directional light aimed at the texture. There might also be a need for some light effects on the menu later on, so i think this will do just fine for now.

Thanks again!

7

Hmmm sorry to bother again.

Now i do need a shader that does not react to lightning, but renders the texture as if it was diffuse lit (self illuminating?) and has an alpha channel for fading ofc.

Is that possible?

8

Something like that (untested):

Shader "Transparent/Plain Texture" {
Properties {
    _Color ("Main Color", Color) = (1,1,1,1)
    _MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
}

Category {
    ZWrite Off
    Alphatest Greater 0
    Tags {Queue=Transparent}
    Blend SrcAlpha OneMinusSrcAlpha 
    ColorMask RGB
    SubShader {
        Pass {
            SetTexture [_MainTex] {
                constantColor[_Color]
                combine texture * primary, primary
            } 
        }
    } 
}
}
9

Sweet Thanks!