extent attribute not authored on most geometry #103354

New Issue

Michael B Johnson · 2022-12-20T00:25:32+01:00

Michael B Johnson commented

2022-12-20 00:25:32 +01:00

Currently, USD export does not export the "extent" attribute on most geometry.

A properly authored USD file will have the extent attribute authored on all prims conforming to UsdGeomBoundable.
This cached extent information is useful because it allows the 3D range of prims to be quickly understood without reading potentially large arrays of data. Note that because the shape of prims may change over time, extent attributes are always evaluated for a given timecode.

This patch introduces support for authoring extents on meshes and volumes during export to USD.

Because extents are common to multiple kinds of geometries, the main support for authoring extents has been placed in USDAbstractWriter, whose new author_extent method can operate on any prim conforming to pxr::UsdGeomBoundable. The USD library already provides us the code necessary to compute the bounds for a given prim, in pxr::UsdGeomBBoxCache::ComputeLocalBound.
Note that not all prims that are imageable are boundable, such as transforms and cameras.

For more details on extents, see https://graphics.pixar.com/usd/release/api/class_usd_geom_boundable.html#details.

Currently, USD export does not export the "extent" attribute on most geometry. A properly authored USD file will have the extent attribute authored on all prims conforming to UsdGeomBoundable. This cached extent information is useful because it allows the 3D range of prims to be quickly understood without reading potentially large arrays of data. Note that because the shape of prims may change over time, extent attributes are always evaluated for a given timecode. This patch introduces support for authoring extents on meshes and volumes during export to USD. Because extents are common to multiple kinds of geometries, the main support for authoring extents has been placed in USDAbstractWriter, whose new author_extent method can operate on any prim conforming to pxr::UsdGeomBoundable. The USD library already provides us the code necessary to compute the bounds for a given prim, in pxr::UsdGeomBBoxCache::ComputeLocalBound. Note that not all prims that are imageable are boundable, such as transforms and cameras. For more details on extents, see https://graphics.pixar.com/usd/release/api/class_usd_geom_boundable.html#details.

Michael B Johnson self-assigned this 2022-12-20 00:25:32 +01:00

Michael B Johnson commented

2022-12-20 00:25:32 +01:00

Added subscriber: @wave

Omar Emara commented

2022-12-20 10:24:20 +01:00

Added subscriber: @OmarEmaraDev

Omar Emara commented

2022-12-20 10:24:20 +01:00

Changed status from 'Needs Triage' to: 'Needs User Info'

Omar Emara commented

2022-12-20 10:24:20 +01:00

This patch introduces support for authoring extents on meshes and volumes during export to USD.

Did you mean to submit this as a diff? Or is this supposed to be a design task? Did you talk to the module about that already?

> This patch introduces support for authoring extents on meshes and volumes during export to USD. Did you mean to submit this as a diff? Or is this supposed to be a design task? Did you talk to the module about that already?

Michael B Johnson commented

2022-12-20 19:21:46 +01:00

Yes, we have a fix, but ran into a snag. Hopefully we’ll sort it out shortly.

Omar Emara commented

2022-12-20 19:33:15 +01:00

Changed status from 'Needs User Info' to: 'Confirmed'

Bastien Montagne added this to the Pipeline, Assets & IO project 2023-02-09 15:39:30 +01:00

Philipp Oeser removed the

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extent attribute not authored on most geometry #103354