TransformUnderMouse with Alpha pixels check for quad-based Transforms

[michalis]

@phomm

The fact is, in the test project all quad-objects are placed in editor without any hierarchy, while in the game I use hierarchy and design-files, in this case the calls to just LRay.Info(LRayNode) are giving not the full picture, so I decided to add cycling through LRay.Count, which helped me to address transient objects (namely the quads with sprites) inside TCastleTransformDesign which hides them.

The TRayCollision.Info indeed returns only part of the information, it returns (from this comment):

the first TRayCollisionNode on the list
except it doesn’t return TRayCollisionNode that relates to
internal TCastleTransform (that has csTransient
flag is ComponentState).

I found that this is always, or almost always, all that you need, that’s why we advise to not iterate over this list yourself ( castle-engine/src/transform/castletransform_initial_types.inc at 8ce77b04e4420cfd4b9032aff43e7e883eaa8824 · castle-engine/castle-engine · GitHub ).

I’ll investigate your testcase to see why it was necessary, thank you – I will want to address it as I design the promised “new hit API”, TCastleViewport.PointingDeviceHit, mentioned in one of the posts above. I will want to account for this.

@phomm

I also noticed that in test project TCastleImageTransform with non-rect textrure (I changed 1 of scenes to image) is not behaving the same way as TCastleScene which we were testing before. If you try to test, you will see, that LRay.Count is reported as 3 for imageTransform (same as for scenes), but it didn’t come to PC or TxC debug line (which stands for PixelCheck and TextureCheck), and that means LRayNode.Triangle is not accessible for this kind of workflow. The reason could be that TCastleImageTransform is not having PreciseCollisions property which is needed.
So maybe some additional adjustment for TCastleImageTransform is needed for alphapixel check to be performed (or one could use alternative TCastleScene for it).

Ah, indeed. Internally the TCastleImageTransform is actually using the TCastleScene, but indeed there’s no TCastleImageTransform.PreciseCollisions so there’s no information about the exact triangle hit and position within that triangle.

Hm. I decided to just add it Done in Add TCastleImageTransform.PreciseCollisions · castle-engine/castle-engine@d8ed28d · GitHub .

It will be available in downloads soon, once the commit titled " Add TCastleImageTransform.PreciseCollisions" is no longer visible on this page.