To run physics simulations and set up PhysX ragdolls, rigid bodies, and constraints, you want to use the NVIDIA PhysX plug-ins for the DCC tools. For the latest 3ds Max Interactive, the PhysX plug-in version is now 3.3.21117.04582, and the PhysX library/SDK used is 3.3.4.

To install the PhysX plug-in for your DCC tool:

1. Download the plug-in from the NVIDIA plugin download page.
2. Follow the instructions in the NVIDIA installer.

When installed and loaded, the PhysX plug-in adds a PhysX menu to the main menu bar in your DCC tool, giving you easy access to tools and documentation for creating PhysX ragdolls, rigid bodies, and constraints.

Note: This version of 3ds Max Interactive does not support the PhysX SDK version 3.4 available for 3ds Max 2018 and Maya 2018, and you may have trouble importing ragdolls and apex cloth. Use the PhysX SDK version 3.3 for 3ds Max 2018 and Maya 2018 when setting up the physics resources in the interactive.

When exporting PhysX data from Maya or Maya LT to 3ds Max Interactive, ensure you specify the correct unit scaling for export. 3ds Max Interactive requires the data in meters.

You’ll find that the scaling for exported PhysX data is handled in File > Export All (or Export Selected) > Output Scaling Factor. Depending on the conversion units selected in the Output Unit, the Scaling Factor displays the scale factor for the exported units. To manually add the scale factor, enable the Custom Scaling. The Output Unit is set to meter by default.

This ensures the correct correlation between meshes, PhysX actors, and global-anchored joints in 3ds Max Interactive with the unit or coordinate system you use in Maya, and the unit you set for your FBX scene export.

Note that the Axis Orientation is also an important consideration during export when using PhysX. If any of the PhysX data contains any globally expressed position (such as initial velocities, or free-anchor joints) these cause difficulties when simulated in the interactive engine. To avoid issues, export the asset in Z-Up. If your PhysX setup does not contain any of these, you can export in Y-Up or Z-Up. For example, simple meshes without PhysX constraints and Ragdolls export correctly with any coordinate system.

3ds Max Interactive uses SI base units, so mass values are in kg, densities are in kg/m3, and the default density value (water) is 1000.

PhysX actors created with the NVidia PhysX plug-in for your DCC tool and exported to 3ds Max Interactive use grams as the base weight unit. In order to align with the units of mass expected in the interactive engine, these actors are converted to kg at runtime.