Can't paint over certain parts of my model, even though they are on the udim

[Miha G]

I'm working on this project and for some reason I can't paint over some parts, but it's showing up on the preview. I checked the UDIMs and I don't have any overlapping shells or geometry. Help please?

[Carlosan]

All the uvislands are on the first quadrant ?

All UV coordinates should be in the range 0.0 to 1.0 and fit within the first quadrant in the UV editor.

[Miha G]

11 minutes ago, Carlosan said:

All the uvislands are on the first quadrant ?

All UV coordinates should be in the range 0.0 to 1.0 and fit within the first quadrant in the UV editor.

yes they are. I'm using 4 UDIMs and all the shells are inside those 4 if that's what you mean.

[Carlosan]

I mean on this quadrant

Try adding a layer at Top and paint on it

 

the parts that can't be painted, have proper UVs ?

is the texture resolution very small ?

[Miha G]

43 minutes ago, Carlosan said:

I mean on this quadrant

Try adding a layer at Top and paint on it

 

the parts that can't be painted, have proper UVs ?

is the texture resolution very small ?

I'm new to 3d coat and can't find where that texture editor is. But the UVs are proper and the resolution isn't small. Also the layer on top didnt work. I opened it in maya and I can add textures over those parts without any stretching or issues 

[Carlosan]

Could you share the model part (by pm) to take a look ?

[Miha G]

14 minutes ago, Carlosan said:

Could you share the model part (by pm) to take a look ?

its not letting me private message you

[Carlosan]

The model has 4 uDims and 4 Materials (that has the same shader type assigned)
Separate by materials if you have -like ex- SSS shader

You dont need 4 materials to separate uDims

 

Also the UVisland is very small, there is not pixel density to paint over

 

Once I resize the UV island that can not be painted,

the issue was solved

 

I found that UV islands are distributed on several UV spaces, put all islands related to uDim_1001 on UV square 1001, islands related to uDim_1002 on UV square 1002 and so on

This works best if all objects share the same uv layout.

 

Take a look at this videos taht show how uDims works on 3DCoat