Since | 18.0 |
<type> usd_primvar(<stage>stage, string primpath, string name)
<type>[] usd_primvar(<stage>stage, string primpath, string name)
<type> usd_primvar(<stage>stage, string primpath, string name, float timecode)
<type>[] usd_primvar(<stage>stage, string primpath, string name, float timecode)
This function returns a value of a primvar on a given primitive.
<stage>
When running in the context of a node (such as a wrangle LOP), this argument can be an integer representing the input number (starting at 0) to read the stage from. The integer is equivalent to the string form referencing a particular input, e.g., “opinput:0”.
You can also use this argument to refer to a USD file (e.g., “/path/to/file.usd”), or to another LOP node’s cooked stage using the op:
as the path prefix (e.g., “op:/stage/lop_node”).
primpath
The path to the primitive.
name
Primvar name (without namespace).
timecode
The USD time code at which to evaluate the attribute. A USD time code roughly corresponds to a frame in Houdini. If not given, the time code corresponding to the current frame is used.
Returns
The value of an existing primvar, or zero/empty value if the primvar does not exist. Use usd_isprimvar if you want to check whether the primvar exists.
Examples ¶
// Get the value of some primvars on the cube primitive. vector vec_value = usd_primvar(0, "/geo/cube", "vec_primvar_name"); float values[] = usd_primvar(0, "/geo/cube", "primvar_name"); float value = usd_primvar(0, "/geo/cube", "primvar_name", 3); v[]@foo_at_current_frame = usd_primvar(0, "/geo/sphere", "foo"); v[]@foo_at_frame_8 = usd_primvar(0, "/geo/sphere", "foo", 8.0);
See also | |
usd | |
usd_primvar |
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