Transparent shaders that do not glow with the bloom effect?

I found an old message from Aras referring to Unity 1.5 and how transparent shaders would not write to the alpha channel and hence would not affect glow. Unfortunatly, I guess something must have changed along the way because they certainly seem to be glowing for me.

Anyway, I’ve been using a custom shader from the Wiki, which I think was called Unlit. I’ve adapted that to use alpha masking, and this doesn’t glow because there’s no blending, just masking. However, I need some alpha transparency in the scene too, and I’d like to keep it consistent with the other materials, so I’d like to adapt the unlit shader to use alpha transparency, but not have any effect on bloom.

I don’t need someone to do it for me, but a finger pointing in the right direction would be a big help.

For reference, here’s the original shader:

Shader "Custom/Unlit" {

    Properties {
        _Color ("Main Color", Color) = (1,1,1,1)
        _MainTex ("Base (RGB)", 2D) = "white" {}
    }
    Category {
       Lighting Off
       ZWrite On
       Cull Back
       SubShader {
            Pass {
               SetTexture [_MainTex] {
                    constantColor [_Color]
                    Combine texture * constant, texture * constant
                 }
            }
        }
    }
}

To use alpha masking, I just changed it to:

Shader "Custom/UnlitAlpha" {

    Properties {
        _Color ("Main Color", Color) = (1,1,1,1)
        _MainTex ("Base (RGB)", 2D) = "white" {}
		_Cutoff ("Alpha cutoff", Range(0,1)) = 0.5
    }
    Category {
	   Alphatest Greater [_Cutoff]
	   AlphaToMask True
	   ColorMask RGB
       Lighting Off
       ZWrite On
       Cull Back
       SubShader {
            Pass {
               SetTexture [_MainTex] {
                    constantColor [_Color]
                    Combine texture * constant, texture * constant
                 }
            }
        }
    }
}

I’m wondering if ColorMask might be the key. Does that designate which channels are written to?

“ColorMask RGB” is the magic line that tells the shader to only write RGB values into the buffer. Since glow is controlled by alpha values if you do not write them to the buffer the object will not glow.

Aha, that’s much easier than it was with my last 3D engine. Thanks for the quick reply, Ethan.