Texel Size ?

CreativeSheep

I'm trying to figure out texel size by means of the object size. How do I calculate texel size by decimal values; by entering in a value of 0.5 for example what exactly is that doing to the object texel density and how is it calculated if that is all the information I can work with ?

Benjammin

Hard to say without knowing what soft you're using. At a guess, I'd say .5 means 0.5 texels/unit, whatever your unit is. Assuming mm, It'll scale up/down your UVs so that the surface area of the mesh is at .5 texels per square mm.

Leinad

I am probably misunderstanding your question, but you'll likely need to provide more detail.

I think I am mixing a few terms together (it's confusing having to consider pixel vs texel vs fragments)

To calculate your texel density doesn't that depend on your texture resolution and uv layout?

When you say "by entering in a value of 0.5 for example" what is this value referring to? Scale? UV-cord?

The texel size of the uv layout should not be changing as you scale up a 3D object transform, right?

This isn't my area of expertise so I may be wrong on some of the details I listed above. Hopefully someone with more knowledge on this topic can reply and resolve your specific issue.

CreativeSheep

@Benjammin the units are whatever the objects imported units are it's 1:1. Therefore if I set it to 0.25 it will be 0.25 texel units; the lower the value the smaller the texel unit.

Benjammin

@CreativeSheep What software are you using? What happens to you UVs when you change those numbers? Can't really help without more info. As @Leinad pointed out, you need to know what your texture resolution is, as texel density is a ratio (pixels/unit).

CreativeSheep

@Benjammin the texture resolution is 4K; the software is Mari. Although when Mari imports and object it's a 1:1 rather then in some software whereas the software automatically converts to CM for example.

The objects coming out of the 3D package in to Mari are that of meters. Therefore as you mentioned texel density is based on a pixels \ unit. Then in this case the texel size in this case would be; 0.000244 ?

I'm dividing 1 / 4096

Benjammin

@CreativeSheep I'm afraid you're kind of on your own with the math, but a "standard" is something like 10px/cm, which equals roughly 1K per meter. I use Maya; I punch in a couple numbers and know exactly what my texel density is. 🙃

myclay

Its about this here?;

Patches>Resize Selected>Geometry Metric

I haven´t found an answer yet but have asked in the discord group for Mari.

https://discord.gg/8FnDbzw

Thomas1994

Determine the size of the object in pixels. For example, if the object is 100 pixels wide on the screen, then that is the object size.

Divide the object size by the decimal value to get the texel size. For example, if you enter a value of 0.5, then the texel size would be 100 / 0.5 = 200 pixels.

watch the video, it's helpful https://www.youtube.com/watch?v=iL2iXizf9xM&themeRefresh=1

mawilbolou

Excellent guide to Texel Density - Yes its paid, $8 but super valuable.
https://leonano.gumroad.com/l/texeldensity

dimwalker

I'm sure other guys will correct me if I'm wrong, but maybe the way to go is comparing face surface area to pixels inside corresponding UV face?

iam717

zbrush uv does this right? even if we have to edit it a bit after for our own needs but useful info on how we can calculate it, via plugin or if blender could also do it if it doesn't already, not sure i always just zbrush them then organize them after in max/blender as needed.  Just toss another option out there, used to eye ball it.  i'd like to hear more if there needs to be more said.  cool thread.