Wrong physical behavior (or?)

Discussion in 'Modeling' started by Hauke Maier, Mar 20, 2020.

  1. Hey guys,

    i set up an 3D-Model with Tinkercad.com to design a Halfpipe, where a UR5+3F-Gripper should follow the shape.
    Unfortunately the halfpipe behaves like a box so that no gripperfinger can access it.
    Is there a setting wrong? Or any other idea?

    Attached you can find the Object itself and a screenshot which describes the behavior


    Attached Files:

  2. I tested it with different stl-files. It seems that error is consistent.

    Help would be nice. Thanks in advance :)
  3. Mujoco uses a convex collider. Your mesh gets replaced by its convex hull. Its not an error.
  4. Thanks for reply Florian! I tried to set convexhull-value on false according to XML Ref. , but was not helpful. Is there any solution on my problem?

    convexhull : [false, true], "true"
    If this attribute is "true", the compiler will automatically generate a convex hull for every mesh that is used in at least one non-visual geom (in the sense of the discardvisual attribute above). This is done to speed up collision detection; recall Collision detection section in the Computation chapter. Even if the mesh is already convex, the hull contains edge information that is not present in the mesh file, so it needs to be constructed. The only reason to disable this feature is to speed up re-loading of a model with large meshes during model editing (since the convex hull computation is the slowest operation performed by the compiler). However once model design is finished, this feature should be enabled, because the availability of convex hulls substantially speeds up collision detection with large meshes.
  5. setting convexhull : [false, true], "true" will not alter Mujoco as to work for general meshes. What you need to do (at least collision-wise, you can leave your mesh for pretty rendering) is to supply a convex decomposition of your geometry. You could look into VAHCD.