usd2sdf: capsule and ellipsoid geometries are not exported

[scpeters]

Environment

• OS Version: macOS 14.7 (Sonoma)
• Source or binary build? source build of main branch (178e136) with Gazebo Ionic

Description

• Expected behavior: if an input file contains collisions with ellipsoid and capsule geometries, the converted output should as well
• Actual behavior: ellipsoid and capsule geometries are not converted

Steps to reproduce

1. Build gz-usd
2. Download the shapes.sdf test world into the gz-usd build folder as simple_shapes.sdf
3. From the gz-usd build folder, convert to USD with the following command:

./bin/sdf2usd simple_shapes.sdf simple_shapes.usda

4. Verify that the simple shapes have been converted to USD (note that the last pair of def Sphere calls have a scaling parameter set and are for the ellipsoidal collision and visual):

$ grep geometry simple_shapes.usda
                def Cube "geometry"
                def Cube "geometry" (
                def Cylinder "geometry"
                def Cylinder "geometry" (
                def Sphere "geometry"
                def Sphere "geometry" (
                def Capsule "geometry"
                def Capsule "geometry" (
                def Sphere "geometry"
                def Sphere "geometry" (

5. Convert simple_shapes.usda back to SDFormat

./bin/usd2sdf simple_shapes.usda simple_shapes_round_trip.sdf

6. Check for <capsule> and <ellipsoid> in the round-trip SDFormat file

$ grep '<capsule>' simple_shapes_round_trip.sdf
$ grep '<ellipsoid>' simple_shapes_round_trip.sdf

Output