Start working on scene usd/en

So, you need to start working on an animation scene. The process of opening the scene is a little different from what you might have seen on other projects.
We use Pixar's USD format to store anim_prep (scene layout prepared for animators), so you won't be able to open the scene as usual.
Also a link to anim_prep scene is live, so when layout team add new assets to the anim_prep scene, they will also appear in your animation scene.
To do this, we use a plugin from Animal Logic, AL_USDmaya, with our inhouse modifications.

How to build scene?

You only need to follow this procedure the first time you open a scene, after building and saving, you will be able to open the scene as usual.

1. Always start building a new scene with empty scene, then select Wizart Animation => USD => Start From Anim Prep from the menu.

2. A dialog box will appear where you need to select the name of the Episode and the name of the Scene you want to start working on.

3. Then click Import.
After a successful Import, you can save the scene to your working folder, and then you can open and save the scene as usual.

As a result of Import operation will be created:

• A Proxy Shape object AL_USDmaya will be created with a link to the latest version of the USD scene via wref.
• The Frame Range from the USD scene.
• A link to the latest version of the sound will be created as a may reference via wref.
• Will automatically be put down in the scene pin on the Wref Context of all Maya's rigs. This means that you will need to switch the rig versions explicitly through The Wref Context Manager,
  if needed. All other files referenced in scene we don't pin, so latest available versions will be loaded.

Warning

In any case, do not manually correct the path to the files, it can break the entire pipeline. If you have a problem with the scene, please email support.

Working with the USD scene

The entire scene is loaded as a USD Proxy, and a minimum number of maya nodes are created.
Characters have no rig loaded at the start, but they should be displayed in the starting position.
To see the real hierarchy of the scene, you need to open USD Outliner. To do this, select Wizart Animation => USD => AL USD Outliner.

The created panel can be docked to Maya's UI.

In the beginning, you need to decide on which characters or items you need to load rig.
It may not be all assets, for example, the assetin this scene is static, or the supervisor animator has given you the task to animate only certain assets.
To switch the asset from cache to rig, select the asset in USD Outliner, and right-click in the context menu Variants=>animDisplayVariant=>rig.
This will download the maya reference onto the asset, and it will have to move to the same location as it was set in the USD scene.

Warning

Asset references are now managed by the AL_USDmaya plugin, and the Department that prepares anim_prep. If your scene is missing an asset, contact support.

Warning

Since this plugin controls the creation and on/off of references, in no case can you use the Reference Editor and edit references manually. This can lead to crashes.

Working with Wref Context Manager

All paths in the scene, including USD Layers, Maya references, texture paths have a wref format. Such paths usually doesn't include reference to a specific version of the asset and normally you do not need to change this in the process. However, animator's work may require to define version explicitly:

• For example, when you start working on a scene, you want to pin the rig versions for a current scene, so that you can take a newer version while working on another scene.
• You have found some technical issue in the rig, and want to update version of the rig to a newer one in the scene explicitly and locally not breaking anything else.

For this purpose we store a special wref context in the Maya scene applied both in Maya and in USD. This wref context update the wref path to a physical path on disk.

To change versions and pin them easily there is a special UI, Wizart Animation => USD => Wref Context Manager.

In the appearing window you can pin on certain wref paths to pin the current versions. Also there you can switch to the desired version and pin it, remove pin, or update to the latest.

• The Version column displays the current version of the file used in the scene.
• If this version is pinned, the icon in the Pin column is set to:
• If the path has no pinned version, the icon in the Pin column is set to:

Warning

If no version is specified in the wref path and no pin is assigned, the current latest version of the file will be used. If a specific version is specified in the wref path and a pin is assigned, the pin value will take precedence.

• You can pin the version by entering the desired value in the Version column.
  
• The second way to replace the version is to select one or more rows, click the right mouse button to cause the context menu and select Pin.
  
• You can pin the latest at the moment version using the context menu item Update to latest
  
• To remove pinned version (unpin): select one or several lines, click the right mouse button to cause the context menu and select the item Unpin.

In the Show menu, you can filter paths by extension: USD files (.usd,.usd,.usd), Maya files (.mb,. ma) and Other Files.

Using the Refresh button you can refresh the Wref Context Manager window after the scene is reloaded. The physical path to the file with the current context settings can be found in the Resolved column.
By default, the column is hidden, you can show it as follows: context menu by table header => Show/Hide Resolved.

Working with the camera in USD scene

You can import a camera rig into a scene if you need to attach an object to the camera, freeze the camera movement, or hide the camera from the viewport.

1. Select AL USD Outliner from the Wizart Animation menu.

2. Select the camera and activate its rig. Now you can mute its movement, or constraints to it any object.

Если вам понадобится скрыть камеру в сцене, вы можете найти её через Outliner в самой Maya и скрыть там, используя клавиши Ctrl + H (для отображения камеры используйте Shift + H).