48. Troubleshooting

In case you experience problems, read these instructions on how to report your issues: How To Report Issues.

48.1. The mechanical system is rigid. Parts seem strangely interconnected

This is most likely because all the components are in the same rigid body. Try right clicking on the single body in the Simulation Structure and selecting Split to split the model into several rigid bodies.

48.2. The simulation Structure is empty (or is missing parts) even though the 3D model is open in SpaceClaim

For the add-in to recognize the model as rigid bodies, all the solids need to reside within components.

48.3. The result of a simulation reveals large interpenetration between solids

The accuracy of the simulation is dependent on the Simulation Frequency. If the simulation is unstable or you experience bad contact behavior, simulation frequency is probably too low for the velocities/feature sizes. Try the Simulation Report to get an estimate for the Simulation Frequency for your simulation model.

Other reasons might be:

• The material stiffness is too low. Increase the Young´s modulus value for the material pair.

• The force range on motorized joints is to high - Make sure you are using realistic values for the motors.

48.4. The simulation behaves completely differently when I change non-related feature or parameter

This is likely due to the physical constitution of the actual system that you are analyzing. Some mechanical systems are simply very or even infinitely sensitive to changes in initial conditions, material or geometric properties. Some systems are so sensitive by definition that even seemingly irrelevant adjustments that initially change say the 50th decimal of some property can have a noticeable impact on the simulation. A very small change in initial conditions will result in an exponential deviation from the original system. Do note, that this is a consequence of real physics, and not poor simulation fidelity (provided the simulation is setup properly). This type of system exhibit even greater scatter in the real world.

48.5. The add-in becomes non-responsive during simulation

This is most probably due to a large and complex model with lots of contacts. Currently there is no way of aborting a running simulation. General recommendations:

• Add Joints between Rigid Bodies (instead of relying on contacts). It will disable contacts between them.

• Disable collision for solids which are not relevant for the simulation.

• Simplify your models before running a simulation, i.e. remove non-relevant geometry such as holes etc.

• Merge rigid bodies.

• Make sure the Simulation frequency is not unnecessarily high.

• If you have many objects colliding, for example in an conveyor typ of scene, you can choose Iterative solver in the material setting between the objects.

• Reduce the tesselation for the collision geometry by reducing the rendering quality: “File” / “SpaceClaim Options” (see bottom of pop-up) / “Popular” / “Rendering quality” (try some of the lower settings).

• Deactivate rendering of contacts.

48.6. Joints are not rigid

If you experience that joints (hinges etc.) are not behaving correctly, swaying/translating whereas they should be rigid, it could be the result of a simulation error. In this case, use the Direct solver for contact friction.

48.7. Gears are jamming or overlapping

Due to modeling of gears as well as the tessellation of the gear solid into triangle meshes, some geometrical jamming can occur. Try to reduce friction and restitution between gears to zero.

48.8. SpaceClaim is busy for a long time after stopping recording of a simulation or Playback of a recording is slow

This might be due to that your Working Directory is set to a slow disk. Perhaps your user account is located on a network disk? If so, change your Working directory to a fast local disk on your computer for optimal performance.

48.9. One or more of the windows are missing

Due to a problem in the current version of SpaceClaim, the Property window and Simulation Structure sometimes do not show up when starting SpaceClaim. If this happens, open the SpaceClaim Options and select Reset Docking Layout in the Appearance settings.

48.10. Keyshot’s animation-button is greyed out

Your keyshot-version might not support animations. See KeyShot exporter for more information.

48.11. There is one extra rigid body in the simulation structure

The Simulation Structure might show one extra rigid body when working with external components, linked from external files. This could especially happen when there are multiple references to the same external component in the document and these components are made independent. If this happens, try to restructure the Structure tree in the Structure panel by e.g. flattening groups of components or rearranging the components in the Structure tree.

48.12. Granular bodies are tunneling the geometry in the scene / Granular collisions appear to not be detected against the geometry.

This is likley due to an insufficiently low time step for the given granular size and speed. Granulars with high speed can move past thin geometries and thus the collision is unable to be properly detected in the engine. Try lowering the time step to properly catch the granular-geometry collisions.