Another UV texel density question

Fuiosg

For characters is there any general guidelines on how much you should scale up UV islands relative to each other? I'm using UE4 and am wondering if there could be some weird mipmap changes if the islands are not the same size; yet I also think it's ridiculous for insignificant texture areas to take up the same amount of space as those that need more detail.

Lately I've been equalizing the size of all islands then scaling up the areas that need the most detail by 25%.

Quack!

Fuiosg said:

Lately I've been equalizing the size of all islands then scaling up the areas that need the most detail by 25%.

This is a fine practice, but be careful.  Texel density mis-match is one of the first things players will notice 'wrong' with a game, so if the mis-match is apparent on the character then that increases the risk of that happening.

I have a 75% 100% and 125% uv shell pile. I normalize all of my shells, then scale them smaller if they are low priority and scale them up if they are high priority, as long as they don't cause crazy mis-match.  If you are finding you have a TON of low priority shells, then you are over-modelling your object.

JedTheKrampus

It can also cause texture cache thrashing, causing a minor perf impact. Just use uniform texel density and have another LOD with different, high detail textures if you need to look at someone's face in a cutscene IMO.

If something is insignificant enough that you want to scale it down, maybe it shouldn't be there at all (like the underside of a table.)