Import obj with UDIMs?

Development Asset Creation
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1

Hi,

I’m trying to reproject textures onto simple remodelled geometry from maya (exported as an .obj)
It has UDIMs (1001,1002,1003,1004).
On model import in RC, it say`s a texture coordinate u or v is bigger than 1.

I thought that RC can handle imported models with multiple UV-tiles?

cheers

markus

2

Hi Leif

Can you send me the OBJ with the UDIMM layout for inspection ?

3

Hi Leif

So inspecting the UVs

So you can see the UVs are not OK

Incomplete_UV.png

recreating the missing UVs

recreate_UVs.png

result in

Screenshot 2016-11-22 09.43.20.png

So there is something wrong with the UVs

4

okay, the problem seems to be solved for the obj.

thank you so much!!!

5

Hi Milos,

I sent you an email on the 14th with an obj (also attached to this post) which also fails to import (having worked ok previously). I checked it in Mudbox and it got the following…

UV_ProblemNoProblem.png

Since this problem is related to smoothing in Mudbox, it doesn’t seem applicable to RC. Is it possible that RC is being a bit over zealous in checking UVs and flagging things that won’t cause issues here?

Furthermore, even though Mudbox ‘warns’ that it has detected problems, it still gives the user the option to import the file. RC on the other hand just refuses, which seems unnecessarily strict.

Thanks

Edit:

I’ve just realised that it’s not the UVs causing the error here, but the actual geometry. Mudbox is saying the this is a problem…

GeometryFail.png

If this is also the reason the obj won’t import into RC then please consider relaxing the ‘rules’ because this really shouldn’t be considered illegal geometry.

6

Hi IanB
We have defined strict policy only for cases which cause memory leaks or crashes later in the pipeline… in photogrammetry you need a bit strict rules as the algorithms used here are quite different from ordinary 3D software solutions…

7

I double checked the situation and it actually is the UVs rather than the geometry which causes the OBJ to not import. Even the most simple OBJ with UDIMs gives this error:

UDIM_Error.PNG

This is what the geometry and UVs look like:

UDIM_Cubes.PNG

Could you please take a look and see why this isn’t importing. The OBJ is attached.

Also, regarding the checks that are done when importing geometry could you explain these and include these in a FAQ? I anticipate many people having problems having similar issues unless they’re aware what the rules are.

Thanks

8

Hi IanB
Please take time to read a bit about the UDIMs here: https://www.fxguide.com/featured/udim-uv-mapping/

We are looking into this, will inform you about the progress…

9

So just to clarify - importing a OBJ with UVs across multiple UDIM tiles is not currently supported, right?

Cause I’m getting the same error when trying to import my mesh with multiple UDIM tiles into my scene (Error message: “A texture coordinate u or v is bigger than 1”)

10

Hi Akin Bilgic

Hope you have read carefully this https://www.fxguide.com/featured/udim-uv-mapping/

So going over 1 in UVs mean you have NOT a UDIM layout…

11

I may be misunderstanding something in Reality Capture’s implementation - but I’m very familiar with UDIM workflow.
UDIM tiles DO go over U 1.0 and V 1.0 in UV coordinate space.

Attached is an example cube I tried to import into my Reality Capture scene, with each of it’s faces on a different UV tile (UDIM’s 1001 to 1006) Is there something I’m missing? Or is importing a mesh with UV tiling not supported yet?

12

I also don’t understand how UDIMs are supposed to be supported if values can’t be greater than 1. I’ve read the fxguide article and can’t see anything which explains this.

How *are* UDIMs defined if not by values outside the 0-1 range?

13

Did this post carry on somewhere else?
Are UDIM’s supported or not.

14

IanB wrote:

I also don’t understand how UDIMs are supposed to be supported if values can’t be greater than 1. I’ve read the fxguide article and can’t see anything which explains this.

How *are* UDIMs defined if not by values outside the 0-1 range?

Christopher Parent wrote:

Did this post carry on somewhere else?
Are UDIM’s supported or not.

I really would like to have answer to these questions.
I have been struggling with this issue for quite a while now and seem to not getting proper answers anywhere.

15

I’d like to know if this was fixed as well. Unfortunately my license ran out a few months ago and I really don’t want to renew it and find out stuff like this still isn’t working.

Could someone try importing the cubes OBJ I attached on the previous page and post the results?

16

+1 to knowing if there is any progress.

UDIMs are very important to my workflow.

17

Tried it and got:
a texture coordinate u or v is bigger than 1
Sorry!