Grab doc and grabber unexpected results for alpha midpoint.

[Turchik]

I was looking into making some alphas and using the grab doc or grabber to capture them. When displacing the mesh both positive and negative along the plane I get results that are unexpected. I used drag dot with a circle alpha positive and negative on a flat plane with the same value. i’d expect one to be black, one to be white, and the rest of the plane to be 50% grey. But upon exporting it wasn’t so the circles were 100% black and white but the grey value was 58%. thinking there may have been an issue with how I was applying strokes. I modified a plane really quick in maya pulling faces equal distances above and below the 0,0,0 grid. I tried setting the Plane Elev to 0 instead of -1 in Zbrush as well. I still get 58% grey for what should be the mid point.

Also it may be helpful if the Midvalue was mapped from 0-255.

Thanks

[beta_channel]

looks like a linear mid

[Turchik]

Ok I guess that makes sense. I have no real knowledge of linear color space but I looked some things up generally it seems linear color space isn’t something we generally work with, but what images get converted to by software before rendering. Be nice if I could export/convert out of Zbrush as sRgb 2.2.

[Turchik]

Ok I thought I’d give one more test. and surprising I got the result I wanted. After capturing the alpha with grab doc or the grabber hit the Make texture button. When converted to a texture it fixes or adjsut the gamma to what I’d expect and i get 50% grey. It does however become 8 bit vs 16 bit in the alpha.