UDIMs

Mari to Modo with just one click by Xuan Prada

UDIM workflow has been around for the last 10 years or so. It became more popular when Mari came out and these days it’s being used by everyone in the vfx industry.

In this blog you can find different ways to setup UDIMs in different software and render engines.
With Modo 801 has never been so easy, fast and great!
With just one click you are ready to go!

  • Export your textures from Mari. I always use the naming “component_UDIM.exr” “RGB_1001.exr”
  • Once in Modo, assign a new shader to your asset.
  • Add a new layer with a texture map, as usual. Add layer -> image map -> load udims.
  • Select the UDIM sequence that you exported from Mari.
  • Change the “effect” to point to the desired shader channel.
  • By default Modo enables the option “use clip udim”. You can check this in the “uv” properties. This means that you don’t need to do anything, Modo will handle the UDIM stuff by itself.
  • That’s it, all done :)
  • As an extra, you can go to the image manager, select one single map and check the UDIM coordinate.
  • Another cool thing, is that you can select all the UDIM sequence in the imagen manager, and change the color space with one single click! This is great if you are working with linear workflow or another color space.

Multi UDIM workflow in Modo by Xuan Prada

You know I’m migrating to Modo.
Multi UDIM workflow is on my daily basis tasks, so this is how I do the setup.

  • First of all, check textures and UDIMs in Mari and export all the textures.
  • Check the asset and UVs in Modo.
  • Load all your textures in the Modo’s image manager.
  • Create a new material for the asset.
  • Add all the UDIM textures as image layers for each required channel.
  • In the texture locator for each texture change the horizontal repeat and vertical repeat to reset. And change the UV offset. It works with negative values (not like Softimage or Maya).
  • That’s it. Make a render check to see if everything works fine.

Baking between UV sets in Maya by Xuan Prada

One of the most useful workflows when you are texturing is bake your textures from one UV set to another one.You will need to do this for different reasons, one of them for example could be using different resolution models with different UV mapping or using a different UV mapping for grooming, etc.

The first time I tried to do this in Maya I realize that MentalRay Batch Bake tool doesn't work fine, I don't know why but I couldn't use it.

I solved the problem using Transfer Maps tool for Maya and decided to write down for future chances.

  • Check the different UV sets in Maya.
  • Apply your textures and shaders.
  • I'm using six different shaders with six different texture maps.
  • If you use the Mental Ray Batch Bake tool (common used for baking purposes) and configure all the parameters, you'll realize that the baked maps are completely black. Something is wrong realated with UV sets. Bug? I don't know.
  • You need to use the Maya Transfer Maps tool. Lighting/Shading -> Transfer Maps.
  • Duplicate the mesh and rename to source and target.
  • Select target and his UV set.
  • Select source.
  • Select desired map to bake. (probably diffuse)
  • Select the path.
  • Select resolution.
  • Bake.
  • Your baked texture is ready.

UDIMs in BodyPaint by Xuan Prada

Step by step tutorial.

  • Export your object from Maya with multiple UDIMs.
  • You can start your texture work from scratch or using any kind of baked stuff.
  • Import your .obj geometry in BodyPaint and create two different materials, one for each UV layout created before in Maya.
  • Create a new texture for the color channel of each material, or connect your textures if you baked previously.
  • Drag both materials over the geometry.
  • You can see in the viewport just the last material dragged, because BodyPaint doesn’t handle multi material jobs at the same time.
  • Click on objects tab, select the material for the UV layout 1 channel and check that X and Y offset are both as 0
  • If you click on texture tab you’ll realize that UV’s and texture match perfectly.
  • Select the material for the UV layout 2 and switch the texture used for this material. You’ll realize that something is wrong, UV mapping and texture don’t match.
  • You will need to change the X offset to 100 and then, will work fine.
  • You can change viewport visualization switching from one shader ball to another one.

BodyPaint only allows to work with one material at the same time, so you will need to switch between both materials to paint in a properly way.

UDIMs workflow, Maya to Mari by Xuan Prada

Sometimes is very useful to work with different range of UV’s, specially when you are working with a huge assets and a high detail is needed.
Find below my workflow dealing with this kind of stuff.

  • Unfold the UV’s in different ranges.
  • If you need to bake procedurals, dirtmaps or whatever, keep in mind to change the UV range in the baking options.
  • I always use the same naming convention.
  • UxxVxx.tiff
  • 0101.tif
  • 2301.tif
  • Create a new project in Mari.
  • Check if the UV’s are placed correctly.
  • Create a new channel called “base” and import your baked textures into it.
  • Ready to keep working.