Hello,

I have:
1 - Created model in Zbrush
2 - Textured model in Mari
3 - Exported Textures as flat
4 - Loaded in model in Houdini 16 Amarok
5 - Applied UDIM textures

Question:
How to use same texture map(s) / again but now instead color i want to use them as bump or displacement map.
How to do it?

In Houdi things looks like this:
Scene level has
* 2 cameras nodes
* 2 area lights nodes
* My 3D model node
When i click on “Material Palette” i have added “Principle Shader” material
When i dive inside to that shader i have node that comes with that shader named as “principledshader1” (This is default that comes when you create “Principle Shader” material)
I have created extra node there named as “texture1”

Inside “principledshader1” When i select “texture1” node i get options and selections that are specific to that node.
There i have loaded in my UDIM textures
CUsers/Tann/Pictures/Props/Wapons/Fel dager textures/diffuse.%(UDIM)d.tif
and UDIM box is selected / tick-ed.
This same material is drag droped on to my model (in “Scene view”)

But i do not know how to load in same textures again (note they are UDIM-s)
and how to apply same texture maps again but as displacement OR bump map.

Can you please provide me an example or help me some how?

Best regards
Tanel.V

Below i have added some extra pictures and also video(s).

Delete that texture node, that's just going to cause problems. Enter the texture paths directly into their respective texture paths on the principled shader node. There is a textures tab that takes paths related to the surface shader. The bump/displace tabs have texture paths of their own. If you want to re-use the texture for multiple parameters, enter the same path on those parameters. Using a diffuse map as a bump/displace map will simply displace/bump based on the brightness of the texture, and may not give the result you are expecting. You will get better results when using a normal/bump/displace specific map for those parameters.

Id i delete the Texture node and i will select principle node (inside “Principle Shader” material)
I see options for textures BUT i do not see option for UDIM.
I have UDIM textures (that means mutly tile textures)
Adding it this way i get incorrect result and i see no option for UDIM

in the Documentation:
see “UDIM Filename Expansion”
on the docs for Principled Shader:
http://www.sidefx.com/docs/houdini/nodes/shop/principledshader [www.sidefx.com]

The principled shader has UDIM expansion enabled for all textures whose paths contain the udim formatting string: “%(UDIM)d”.

Thank you.
I wi8ll take a look at this tomorrow morning. It is 01:00 midnight here atm and have to go work tomorrow.
I hope i can find also solution for flip uv-s

It was available for texture node but i did not see it for principle shader.

This is why i started messing around with texture node at first place.
As i did not find option to flip UV-s and that means textures applied to mesh are applied incorrectly

Moin,

as I just responded to your PM, I'm going to do a video on this topic ASAP.

In general you will probably need to adjust your UDIM pipeline to match Houdini's naming convention (please read the documentation linked above, it is quite clear that you cannot use U values for the UDIM offset greater than 8 for example, if the docs are correct).

Flipping U and V readout is possible as your screenshot shows, but that does not affect the texture file naming (as far as I know), because the flipping is done on READOUT, not on filename creation (for example: Reading coordinate 0.1/0.2, when flipped, turns into 0.9/0.8 but NOT into 9.1 or 9.9 or what, since the “value” left of the digit isn't applied to the UV map but to the texture file map, i.e. the naming convention).

As for the naming of the files, you may have missed the logic of “printf” used there. In computer languages, the term “%d” stands for an integer value that gets filled in by the program, not the user (yes, I know, there is sreadf, but let's not get into semantics).
So using “%(UDIM)d” is a slightly convoluted way of saying “give me an integer value made from the UDIM name”. This term (%(UDIM)d) simply *reads* *out* the UV coordinates from your geometry UV attributes and “extracts” the part left of the digit (since that is what a cast to integer does: Cut off everything right to the digit including the digit itself).

A value of 4711.0815 turns into 4711.
A value of 91.123 turns into 91.

If you are having a U value of 5.1 and a V value of 6.4, your %(UDIM)d will yield 1066. Your texture file name for the UV coordinate 5.1/6.4 therefor has to be “whatever_1066_whatever.whatsnot”

Note tha a U value of 9.x and a V value of 0.y will turn into the same texture filename (UDIM) as a U value of 0.a and a V value of 10.b

I hope any of this is of any help …

Marc