Determine bounding box coordinates ordering

[hdefazio]

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[hdefazio]

from @Purg:

[A] We should add a comment about what the intended screen-space order of corners_screen_pos is, extending the comment on line 197.

[B] In terms of values being assigned to variables, it confused me that the "bottom" was being assigned to a "min" vertex, as "bottom" in screen space is the maximal value. It would have made more sense to me to leave the vertex variable assignment the same and change the assignment to corners_screen_pos instead.

[C] Not for this PR, but it seems we might want to change the names of the slots in the detection 3d set message as well. The cardinal direction naming presents a bundled assumption that, in screen-space (2D), the box is axis-aligned. That is not the case in the box resulting from the 3D transformation (not axis aligned in 3D), so those names should be expanded on in a revision.

[Purg]

@joshanderson-kw's comment in that thread stated his originally intended ordering (BL, UL, UR, BR). Is there a technical issue with the current not-exactly-that ordering, or just the (lack of) clarity in the outgoing message attributes?

If we need to change the ordering, I presume that's a relatively easy change to the corners_screen_pos assignment.

I believe that either way we need to update the ObjectDetection3dSet message to use upper_left, lower_left, upper_right, lower_right naming to be more clear in 3D point meanings, adjusting message assignment as appropriate based on the outcome of the above query.

Ramifications of message change: users of that message need to update their code.

• feedback generator
• arui_engineering.unity related scripts that subscribed to object messages for rendering
  • Eventually to be replaced with CU's ARUI components, but I presume this would be a relatively quick fix.