Simulation commands

Use the Simulate commands to control simulations.

Run control commands

• Play — When you use the Play command, Mechatronics Concept Designer switches to runtime mode, thereby disabling most commands and user interface interactions.
• Stop — Stops the simulation, exits runtime mode, and returns to the authoring mode.
• Restart — Restarts the simulation.
• Forward One Step — Plays the simulation in increments.
• Pause — Pauses the simulation and keeps the application in runtime mode.

Tip: You can activate and deactivate some MCD features while a simulation is paused. You can:

• Right-click an object in the Physics Navigator and choose Zoom to Fit when you pause a simulation to monitor an object more effectively when resuming the simulation.
• Activate and deactivate the Rigid Body Color command if you only want to use the rigid body color for a portion of the simulation.
• Reposition and resize sensors while a simulation is paused. This helps with the virtual commissioning of systems such as material-handling processes. You can pause a simulation and right-click a sensor to edit it without ending the simulation. When you stop a simulation, the sensor's edits remain.

• Time Scale — Adjusts the playback speed of the simulation. You can use slower motion to better analyze advanced motion sequences, such as robotic systems that use inverse kinematics.
• Snap Shot — Saves a screen shot of a simulation. Use the Runtime Inspector to display your snapshots and timestamps.

Controlling simulations with operations

• Forward Operation — Plays only the next operation of the simulation.
• Run to This Operation — Plays the simulation to a specific operation in the Sequence Editor.

Simulating only the active displayed part

Use the Parts to Simulate preference to specify whether simulations are performed in all the displayed parts or in only the active displayed part. When Parts to Simulate is set to Active Displayed Part, only the active displayed part is simulated.

Runtime warnings

You can manage what happens to warnings and the overall simulation when a runtime error occurs using the following Mechatronics Concept Designer preferences:

• Ignore Runtime Warning — Automatically ignores runtime warnings. This can be useful when giving a demonstration.
• Pause at Runtime Error — Pauses the simulation when a runtime error occurs.

Optimizing simulation physics calculations

You can select and then tune the physics solver to focus computing power based on simulation requirements, such as setting faster collision and constraint calculations to run virtual commissioning simulations with real-time capabilities.

Example: You can choose a physics solver and tune it to better simulate scenarios requiring large amounts of data processing.

Use the Mechatronics Concept Designer Preferences command to choose from the following physics solver options:

• Bullet Solver — Use this option for standard simulations. If you select the Bullet Solver option, the Mechatronics Concept Designer Preferences dialog box lets you set parameters specifically for this solver type, such as Use Parallel Calculation, Randomize Solving Order, and Error Reduction Factor.
• PhysX Solver — Use this to support multicore processing that may improve the performance of simulations involving numerous collisions, collision bodies, collision shapes, rigid bodies, or constraints. It can also be used for Mesh collision shapes, material-handling processes, and stacking processes. You can use dynamics motion to solve articulation motion with the PhysX Solver option. When necessary, you can use collision detection with flexible cables with the PhysX Solver option.

Tip: Use the Mechatronics Concept Designer Preferences command to more easily tune the PhysX Solver with artificial intelligence (AI) assistance.

Smart Recommendation

Use the Smart Recommendation option to adjust the solver's parameters. When deriving values, consideration is given to the assembly, including the:

• Number of bodies, collision bodies, joints, and actuators.
• Average scale of the collision object and scene dimension.
• Maximum motor speed and travel distance.

Use the Smart Recommendation to calculate the Step Time, Length Tolerance, Speed Tolerance, and Contact Margin. You might need to fine tune the parameters to optimize performance. You can also set these solver options using customer default settings for Mechatronics Concept Designer.

Ground plane and sleeping bodies

Use the Create Ground preference to infer a ground plane in a simulation. Geometry that is assigned a collision body cannot pass through the ground plane.

When an object drops to the ground, the object suppresses to reduce physics calculations and stabilize the simulation. You can apply a force to a sleeping collision body to reactivate it.

Where do I find it?

Command (Application: Mechatronics Concept Designer): Play, Stop, Restart, Forward One Step, Pause, Forward Operation, Time Scale, Snap Shot

Specifying parts to simulate

• Preferences: Mechatronics Concept Designer Preferences → Active Displayed Part or All Displayed Parts

Selecting a physics solver

• Application: Mechatronics Concept Designer
• Command: Mechatronics Concept Designer Preferences
• Location in dialog box: Solver node → Part Settings group → Bullet Solver or PhysX Solver

Using AI assistance for tuning PhysX Solver parameters

• Application: Mechatronics Concept Designer
• Prerequisite: You must use the PhysX Solver option with the Simulation Precision Option set to User Defined.
• Command: Mechatronics Concept Designer Preferences
• Location in dialog box: Solver node → Simulation Precision group → Smart Recommendation