Alpha blend

Krot_Art

hello guys
Plz help me 

I had a necessity to get soft alpha from hipolyно I was not able to get her in xnormal, marmoset, maya 

i only have alpha test, but i need  alpha blend

prompt me to me where and what program can help me to get a quality result without additional manipulations?

Obscura

Hm. I would imagine the shape of your highpoly mesh isn't a plane, in this case its kinda tricky. There is a method that can show your mesh unwrapped - the model flattens out in the shape of the unwrap. So first you would need to unwrap the part of the highpoly, that has the soft opacity part, so the flattening works. Then you can do it the traditional way, which is -> place a camera above the area that needs to be captured. Set the opacity map of the highpoly to be a diffuse map, set the shading of it to be unlit. Capture it from the camera, and thats it. In some cases, like overhanging alpha parts, this still won't work though.

The reason for why opacity baking is still such a pain to do, is in the implementation of the most of the bakers. The ray that is being casted towards the highpoly either stops at the first hit, or at the ray length limit, and takes the result from there. What would need to happen in order to get this properly working is the following:
- A multi pass ray tracing technique
- Possibly, the first pass would go until the max ray length, store how many times it penetrated through anything until it reached the ray length limit, at what distances, per pixel, then use this as pass count, so this would be very much like a pre-pass
- Do traces until it goes through each iteration, store the results in individual render targets, also store the hit opacity from the reference mesh.
- When all of them finished, accumulate the results using some blending technique, such as alpha blend, alpha test, additive,etc.