[Isaac Sim] How to add Spline movement?

I’m trying to simulate moving objects on a conveyor but I don’t know how to do it in Isaac Sim. Here is one similar example in Unreal Engine: Ue4 Tutorial - Moving an Object along a path using a Spline Track - YouTube

Please let me know if you have some ideas. Thanks!

Would something like this help?
curve4.usd (654.4 KB)

When I import this and hit run, there is an warning: “Physics USD: physics scene not found”, and nothing is moving. Do you have any idea why?

I think the problem is not the missing physics scene - Omniverse should create a temporary one if there is none.

I forgot that I had to implement a custom OmniGraph node which needs to be installed as an extension. Unfortunately I may not have the node anymore, it was just an Experiment.

Here is what I did:

  1. Create a curve in Blender to represent the motion path.
  2. Export/import the curve to Omniverse via USD.
  3. The curve is now a mesh which is invisible in the viewport as Omniverse does not yet support curve.
  4. The mesh object contains the curve as an array of coordinates in the „points“ Attribute.
  5. Use OmniGraph to read the point array and update the sphere‘s translation according to the coordinates in the array.
  6. Now the sphere moves along the curve.
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I tried following your guide but in Isaac Sim I cannot find the extension: omni.graph.bundle.action. I’m using Isaac Sim 2021.2.1. Any idea why?

Is omni.graph.action available in your extension manager? Is it activated/autoloaded?

It will be available in our next release

Hi Itorabi,
When you mentioned it’s in the next release, are you referring to a way to follow a spline …or a curved conveyor plugin? I saw that Isaac Sim has a straight conveyor plugin now, but most of us working in warehouse and factory automation need a way to create curved conveyors. It would be priceless. I’ve been trying to write code for one in Unreal Engine, but having a canned solution in Isaac Sim would be amazing. Do you by chance know if that’s on the list for the future?

Hi Sozno,

yes, please stay tuned, In the next release in October we will have curved conveyors


This news made my day!! Thank you so much! I’m really excited for it. It will take my robotic/factory automation simulations to the next level.

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