Each tyFlow is able to export “I_PARTICLEOBJ” and “I_VRAYGEOMETRY” interfaces to 3ds Max. In some cases, enabling these can cause issues between tyFlow and other plugins. In other cases, you might want to limit which particles are sent back to a particle query request. These settings allow you to override these interface exports.
Enable Particle Interface: controls whether the particle interface will be returned when the tyFlow object is queried for its default interface. Returning this interface allows third-party plugins to query a tyFlow for its particles.
Incl. legacy interface: when enabled, 3ds Max’s legacy particle interface (I_PARTICLEOBJ) will be enabled, as well as its modern interface (IParticleObjectExt).
Disabling the “incl. legacy interface” setting can improve compatibility with certain 3rd party plugins.
For example, if you have a PhoenixFD grid which uses a tyFlow as a PHXSource input object, you might only want to use certain particles in the flow to affect the PhoenixFD simulation. By limiting the particles exported through the I_PARTICLEOBJ interface (by setting the desired export groups), you can limit which particles will be returned to the PhoenixFD object.
When a 3rd party plugin asks tyFlow for the scale of a particle, these options let you choose what property of the particle is returned.
Return scale: the explicit scale value of the particle will be returned.
Return shape diameter: the diameter of the particle’s shape mesh will be returned.
Disabling the VRay interface will prevent tyFlow from being able to render VRay instances.