Issues with contacts when using complex geometry

Discussion in 'Priority support' started by Sudeep Dasari, Dec 24, 2018.

  1. Hi,
    I've been trying to create a simulator which can adequately model a Sawyer robot interacting with a set of random objects. I'm using a Sawyer model that I found online combined with object meshes which I've convexified myself.

    Unfortunately, I've run into a bunch of really strange issues with object contacts and the simulator often runs quite slow. Here is a google document with the behavior described: https://docs.google.com/document/d/1c-DOjd4NP55ctrDwCd50tC0CNoyTLupXMs-ciUVL2dA/edit?usp=sharing

    I've also attached a demo XML file which showcases this behavior: https://drive.google.com/file/d/10vWYJkdfnNdFpw7DRwk-8_0Txyht4u8K/view?usp=sharing

    I'd appreciate any tips you have for creating a faster, more stable simulator and creating better contacts. In particular, I've had a hard time creating a single set of parameters that enable grasping, lifting, and pushing tasks with a wide range of objects.

    Thanks for the help in advance, and let me know if I can supply anything else!
     
  2. Emo Todorov

    Emo Todorov Administrator Staff Member

    You have a bowl-shaped object inside the robot pedestal, which is generating over 1500 contacts -- see images. This will slow down any simulation. In general, whenever the simulation is slow, always check the number of active contacts and other constraints (press F2 in the simulator to show info text). If it is much higher than what you expected, that means there is some component of the model that is generating unintended contacts. You can use transparency, contact point rendering and contact force rendering to see where the problem is.
     

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