Normal map implementation in ucupaint is currently over complicated due to support for parallax mapping which is no longer supported (at least without baking). Simplifying the implementation hopefully will improve the performance and shader compilation time.
[x] Remove write height support for normal map since it has a very little use case
[x] End linear bump process should not exist if there's no bump map used
[x] Optimize group normal process
[x] Height and normal layer IO should only exist when needed
[x] #81
[x] Use standard normal map if parallax mapping is not used
[x] Dealing with Bump + Normal map mode since currently it's a bit confusing to use (won't fix for now)
Normal map implementation in ucupaint is currently over complicated due to support for parallax mapping which is no longer supported (at least without baking). Simplifying the implementation hopefully will improve the performance and shader compilation time.