Texel Density & Trim

MamdouhFahmy

Hello , i am working on ornamental door as part of learning how to do trim sheets properly so am working by texel density 2k for 2 meters which is in maya supposed to be 10.24 px/unite but i came across another problem , my understanding is the better way to do trim is to finish the model first to measure accurately its texel density across the uv area which is what i did but the thing is when i followed the rule 100% the area which a trim takes is very small and that resulted in pixelated heightmap in substance desiger, is thats not the way i should do trim ! how do you solve this problem i know i can just make it bigger but that would break the texel consistency specialy for parts thats way smaller , i also attached an image to the door am trying to make so you get the full picture. 

sketchem

Try something like this: 

Feeding the bevel node low-res shapes can have rough results. You can feed it bigger shapes, or upscale your small shape before beveling. Then return to normal res afterwards. I used a levels node to change the output size. You can use any cheap node that doesn't alter your shape. 

Looking at the picture of the door, I think those shapes are so small that you're going to run into problems with pixelation no matter what. 10.24 px/cm, that strip of door is maybe 5cm at most, so you get 51 pixels to work with. That is not many. I think what you have is not bad, try the bevel trick. You can also do a little non-uniform blur on the outer edges to smooth them out. 

MamdouhFahmy

sketchem said:

Try something like this: 

Feeding the bevel node low-res shapes can have rough results. You can feed it bigger shapes, or upscale your small shape before beveling. Then return to normal res afterwards. I used a levels node to change the output size. You can use any cheap node that doesn't alter your shape. 

Looking at the picture of the door, I think those shapes are so small that you're going to run into problems with pixelation no matter what. 10.24 px/cm, that strip of door is maybe 5cm at most, so you get 51 pixels to work with. That is not many. I think what you have is not bad, try the bevel trick. You can also do a little non-uniform blur on the outer edges to smooth them out. 

hey i have tried this upscale the resolution then downscale at the end also using non uniform blur i may have gotten a tiny bit better overall 

look at this i used transform node to make the shapes bigger by 50% more 


its much cleaner now so like you said the area indeed is small so its gonna pixelate if i use 10.24 for 2k  ,  on the other hand if i make it 50% larger would that be ok ! 

poopipe

Fixing Texel density is about keeping the scale of information consistent - not about keeping the resolution consistent.  

UV at 1024/metre
If the resolution is too low, double the resolution of the texture. 
You don't need to touch your model because the relative scale remains the same

It is not the most efficient use of texture memory but it's a trim sheet so it's getting re-used a lot and you're already getting far more for your memory investment than you would be with a unique map.

MamdouhFahmy

poopipe said:

Fixing Texel density is about keeping the scale of information consistent - not about keeping the resolution consistent.  

UV at 1024/metre
If the resolution is too low, double the resolution of the texture. 
You don't need to touch your model because the relative scale remains the same

It is not the most efficient use of texture memory but it's a trim sheet so it's getting re-used a lot and you're already getting far more for your memory investment than you would be with a unique map.

i am using 2k textures / 2 meter , its a good advice and it would solve the issue because i tried changing to 4k inside substance and it worked , i was searching for another solution because maybe 4k textures are not that common in games ! i honestly dunno 

poopipe

4k textures are very big and you'd have trouble justifying the use of 4k maps for unique props etc.  - (*at a basic level - we'll ignore modern streaming tech)

but
if you have a trimsheet and you are re-using it across tens or hundreds of assets, that big chunk of memory becomes better value 

one question to ask yourself is .. does this texture need to cover 2 metres?  do you need that much variation? 
if it only needs to cover 1m then you re-uv to account for that and your texture doesn't need to get any larger 

MamdouhFahmy

poopipe said:

4k textures are very big and you'd have trouble justifying the use of 4k maps for unique props etc.  - (*at a basic level - we'll ignore modern streaming tech)

but
if you have a trimsheet and you are re-using it across tens or hundreds of assets, that big chunk of memory becomes better value 

one question to ask yourself is .. does this texture need to cover 2 metres?  do you need that much variation? 
if it only needs to cover 1m then you re-uv to account for that and your texture doesn't need to get any larger 

hey thanks for your reply , in my case it covers more than 2 meters and the trim itself would only be used for this door even if its a game environment the details on it are only specific to this door  , your right about having trouble justifying the use of 4k map thats why i am trying to find another solution , i have seen some tutorials for trim sheet am surprised they start the trim before the model and they divide the plan into many trims that takes certain space ! i dont understand how to work this way if i need some consistency in the texel density .

poopipe

if you're not sharing texture with other assets then only use trim techniques where it actually helps and don't be afraid to bump your texel density if that's what you need to make it look right.

at 1024px/metre, 1 pixel is  <1mm across :  at this density you need to get pretty close to a surface to see pixels (even at 4k) so nobody is going to notice if you double density to get a shape to look nice