User guide

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• Currently you can't delete scene graph locations using Look Files, you can only add new locations or modify existing
ones. For instance to hide an object you should set its visibility options rather than pruning it from the scene
graph.
Setting Material Overrides Using Look Files
Following the core principle in Katana that all scene data should be inspectable and modifiable, mechanisms are
needed to allow material settings defined in Look Files to be overridable downstream.
In Katana this is done by bringing the materials into the scene so that the user can use the normal Katana nodes,
such as the Material node in 'override' mode, so make changes.
For efficiency, and to avoid lighters scenes becoming littered with every single material that may be used on any
asset in the scene, the materials used in by a Look File aren't loaded into scenes by default. If you want to set
overrides on the materials you first need to use a LookFileOverrideEnable node. This brings in the materials from the
Look File into the Katana scene and sets them up (by bringing them in a specific locations in the scene graph
hierarchy based on the name of the Look File) so that these instances will be used instead of the ones contained in
the original Look File.
LookFileOverrideEnable also brings in any renderer procedurals for overriding in a similar manner to materials.
Collections Using Look Files
Look Files can also be used to pass off Collections from one Katana project to another.
When a Look File is baked out for a sub-section of the scene graph hierarchy, for every Collection the baking process
notes if any locations inside that sub-section of the hierarchy are in the Collection. If they do the paths for those
matching locations are written into the Look File.
When the Look File is brought in and resolved, these baked sub-collections are brought in as Collections that are
available at the root location of the asset.
In essence this means that if you're using a Look File to pass off the materials and assignments on an asset from
Look Dev to Lighting you can also declare Collections in your Look Dev scene so that they are conveniently available
to the lighters.
Look Files for Palettes of Materials
As well as being used to contain the Materials used by a specific asset, Look Files can also be used to contain general
collections of shaders. This is particularly useful if you want to have studio or show standard sets of shaders created
in 'shader development' which are then made available to other users. Another use of shaders from Look Files is to
11 LOOK FILES | SETTING MATERIAL OVERRIDES USING LOOK FILES