Atoms Supports static xgen collections with Pixar Renderman only.
Exporting xgen collection and meshes
Create an xgen groom on our atoms robot, something like in the picture. Then you can start to export the data needed by atoms.
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First thing you should export the meshes. Please remember to export the meshes after you created an xgen groom. Because xgen add a xgen_Pref attribute on the mesh that renderman procedural uses during the rendering. Export the meshes with the atoms mesh exporter (aotms menu: Atoms > Export > Mesh exporter) or using the variation builder.
Before you can export the xgen collection. Select the xgen collection from the outliner. Open the xgen window and make sure the "Flip to other side of the surface" option is active.
Now you can export the collection. Select the xgen collection and execute from the Atoms menu: Atoms > Export > Xgen Collection Exporter.
Select the head mesh and inside the ui press the select button on the left of the geo field. Choose a output folder and set an output name in the last field and press export.
The tool saves a copy of the currenct collect in the output folder, it renames the colelction usign the output name and it also exports all the materials attached to the descriptions. It creates also a .groom file. This is an atoms file that you will use later to setup the agent variation.
If you want check the content of the .groom file, open ti with python. It's a atoms mapmetadata.
Setup the atoms scene
- Create an agent group
- Add a grid layout module and set the grid size to 3,0,3
- Add a state machine module and set the state to 1
- Add a variation module and se tthe variaiton name to Robot1
Now form the Atoms menu: Atoms > Variations > Import variation json, import the robot.json variation fil from the AtomsMaya\data\variation folder.
Open the Agents Variation Manager from the Atoms menu: Atoms > Variationa > Agents Variation Manager.
Select the atomsRobot from the column on the left. Inside the geometry tab add a new entry press the right mouse button. Set "hair" as key and set the path of the .groom file you exported. Change the robot1_head path with the mesh we exported at the beginning.
Go inside the GeometryGroup tab. Select the Robot1. Add a new entry pressing the right mouse button on the table on the right. On the first field select hair and on the second one select one material. The material you select doesn't influence the hair material because at render time it always use the ones contained inside the collection folder. Press ctrl+s or from the File menu choose "register to atoms" to save the changes.
Exporting caches
The xgen can be renderer only using the atoms proxy node. So you need to export first an atoms cache using the Cache exporter from the Atoms menu:
Atoms > Export > Cache exporter. Select the agent group from the list and press export.
Now you should export an alembic cache because the xgen procedural can read only the mesh animation from an alembic cache.
Open the alembic exporter from the Atoms menu: Atoms > Export > Alembic exporter. Inside the ui select first the agent group on top and then select all the agent on the bottom widget. Select Variations from the mesh mode menu and turn on the "Groom Cache" option. Select an output file and finally press "Run".
Creating an atoms proxy
Create an atoms proxy node from the Atoms menu: Atoms > Rendering > Create Atoms proxy node.
Se the atoms cache you exported before and also the alembic cache you exported. Inside the alembic cache folder you will find a file for each agent, just select one of those files.
Rendering
Create some renderman lights and before hit render execute from the Atoms menu: Atoms > Scene > Setup xgen settings. This will add a mel script to the renderman post world ri injection scripts. This script setup the xgen camera attributes at each frame.
Finally you can start the render.
