Question about EdgeDetectionMaterial in the outline sample

postprocessing
outline

#1

Hello,
I can not understand why the r components are not 0.0.

from line #409
_vec4 c1 = texture2D( maskTexture, vUv + uvOffset.xy);_
_ vec4 c2 = texture2D( maskTexture, vUv - uvOffset.xy);_
_ vec4 c3 = texture2D( maskTexture, vUv + uvOffset.yw);_
_ vec4 c4 = texture2D( maskTexture, vUv - uvOffset.yw);_
_ float diff1 = (c1.r - c2.r)*0.5;_
_ float diff2 = (c3.r - c4.r)*0.5;_

In my understanding the gl_FragColor of ‘maskTexture’ is assigned in line 375
gl_FragColor = vec4(0.0, depthTest, 1.0, 1.0)

I see my problem. Sorry to waste your time.


#3

Hello,I have the same question why the r components are not 0.Could you kindly tell me what’s the problem?