Simulink 3d Animation LinePickSensor detects collision wrong

Hey Guys,

I'm currently working on an university project and facing some issues with Simulink 3d Animation.

When working with Sensor Collisions (LinePickSensor) the ray detects a collision even though there is sight (see below).

Apparently there is a invisible rectangular box arround the mannequin (from feet to head - from hand to hand) which is detected.

When the ball is moved to the left (as far as the ball wouldn't hit the mannequins hand if moved upwards) there is sight.

I don't face those issues when working with objects that don't elements that stick out (e.g. sphere or cube).

Does anyone have a idea what the problem might be?

Thank you!

[Muhammet Dabak]

I have the exact same problem. I guess it is not possible to solve.

MATLAB says

LinePickSensor Uses ray fans or other sets of lines that detect the distance to the colliding geometries.

In your case, that line hits the boundingbox of that object so there is no way out I guess, unfortunately.

[Don Brutzman]

Interesting question. Related low-level information regarding X3D functionality is found at X3D Tooltips: LinePickSensor describes functionality and provides reference links.

If it is X3D "under the hood" then some adjustment of model structure might be useful. I suspect that an overall simplified bounding box (represented in Group or Shape fields for bboxCenter bboxSize) are being used for picking geometry. This is common practice to reduce computational complexity of collision detection.

This is a good topic for our x3d-public mailing list, will pose it there.

Answer 1

[Nishan Nekoo]

As suggested in the post, this is likely due to the collision bounding box of the mannequin.

As the VRML-based viewer has now been deprecated, I would recommend using the Unreal Engine based visualization. For certain actors, you can enable the 'PreciseContacts' property allowing the Unreal Engine to use a collision box that follows the actor mesh precisely.

https://www.mathworks.com/help/sl3d/sim3d.actor.html?searchHighlight=sim3d.actor&s_tid=srchtitle_support_results_1_sim3d.actor#mw_12a9aeff-98a7-42d2-abe5-9304632bcf4d

Nishan