Add collisionShapeId to RayIntersectionT for raycast hit entity ident…

[khalidbourr]

🎉 New feature

Closes #3314

Summary

DART's RayHit already contains mCollisionObject but it was being dropped in GetRayIntersectionFromLastStep(). This PR adds a collisionShapeId field to RayIntersectionT and populates it using the same CollisionObject → getShapeFrame() → asShapeNode() → shapes.IdentityOf() mapping that convertContact() already uses.

Changes

• include/gz/physics/GetRayIntersection.hh
• include/gz/physics/detail/GetRayIntersection.hh
• dartsim/src/SimulationFeatures.cc

Checklist

• Signed all commits for DCO
• Added a screen capture or video to the PR description that demonstrates the feature
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
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• All tests passed (See test coverage)
• Updated Bazel files (if adding new files). Created an issue otherwise.
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Note

Companion PR for gz-sim: gazebosim/gz-sim#3336

[azeey]

This would break ABI and would not be backward portable. Alternatively, we can add an optional data to RayIntersection similar to how force, normal, and depth are added to contact data in

gz-physics/include/gz/physics/GetContacts.hh

Lines 71 to 73 in a1e7ae5

	public: using Contact = SpecifyData<
	RequireData<ContactPoint>,
	ExpectData<ExtraContactData> >;

and

gz-physics/dartsim/src/SimulationFeatures.cc

Lines 278 to 283 in a1e7ae5

	// Add normal, depth and wrench to extraData.
	auto& extraContactData =
	extraData.Get<SimulationFeatures::ExtraContactData>();
	extraContactData.force = _contact.force;
	extraContactData.normal = _contact.normal;
	extraContactData.depth = _contact.penetrationDepth;

[khalidbourr]

I got it, I will do that asap

[khalidbourr]

I’ve refactored the code to follow the same CompositeData / ExpectData pattern used in GetContacts.
collisionShapeId is now passed as optional extra data through ExtraRayIntersectionDataT, so RayIntersectionT stays unchanged.

[khalidbourr]

@azeey Just a gentle ping, in case further modifications are needed, I'm available. Happy to iterate whenever you get the chance to review.

[azeey]

Just one minor comment, otherwise, LGTM! Thanks for the contribution!!

[azeey]

nit: weird indentation

[azeey]

5d0e93f

[azeey]

Actually, on second look, I realized this doesn't have any tests. Would you mind adding one in test/common_test?

[khalidbourr]

Actually, on second look, I realized this doesn't have any tests. Would you mind adding one in test/common_test?

Sure !

[khalidbourr]

I extended the already existed tests: SupportedRayIntersections and UnsupportedRayIntersections.

In SupportedRayIntersections:

if Ray hits sphere then collisionShapeId != 0 (valid hit)
If misses sphere then collisionShapeId == 0 (nothing hit)

In UnsupportedRayIntersections:

Ray would hit sphere but detector can't raycast then collisionShapeId == 0 (must be treated as miss)