Building Parts from a 3D Model

Once you have created the assembly from your 3D model, you can start to add the parts.

This procedure assumes you have set up a mechanism and imported a graphic asset from which you built an assembly. If that is not the case, follow the instructions under Building Assemblies from a 3D Model first.

Follow these instructions for each part you want to create:

  1. In the Explorer Panel, expand the tree to locate the node that you want to use to generate the geometry. As you move around the tree you can see in the 3D View that various nodes on the reference model are being highlighted.
  2. Right-click on the node and select Create Part from the context menu.

    The Select an assembly dialog box appears.
  3. From the Explorer Panel, select the assembly where you want the part to go and click the Confirm button.
    The next time (and subsequent times) you create a part from 3D assets, you will have the option to add the new part to the assembly you just picked:
  4. Right-click on the part in the Explorer Panel and select one of the following from the context menu:
    • Create Collision Geometry > Best-Fit to let Vortex® decide which primitive geometric shape fits the best.
    • Create Collision Geometry > <Shape Name> to pick a specific primitive geometric shape to use.
    • Create Collision Geometry > Triangle Mesh... to generate a triangle mesh.
    • Create Collision Geometry > Convex Mesh... to generate a convex mesh.
    • Create Collision Geometry > Convex Mesh Decomposition... to select a convex mesh decomposition method and specify its parameters.

    If you chose best-fit, Vortex will select the shape that most closely approximates the 3D model from the list of primitive shapes only (convex and triangle meshes are never used). For example, in the image below, the wheel on the left at the front appears with a box collision geometry shape and the wheel on the right at the front appears with a triangle mesh. You can also see the wheel at the back which has no part or geometry at all.
    Triangle and convex meshes are useful when there is a part whose shape does not match primitives such as spheres and boxes, but there is no support for collision geometry between two meshes. In addition, meshes are costly to compute during a simulation, so it is recommended to use primitive geometry shapes whenever possible.
  5. Click the Explorer tab to switch to the Part tree.
    You can now see the newly generated geometries in the tree. By default they are added as collision geometries, but you can change this to buoyancy or drag geometries by following the instructions under Changing the Geometry Type (Collision, Buoyancy, Drag, Lift).