Maxwell renders Maya particles as procedural spheres. The radius can be set by setting the render type to Spheres on the particle shape node, then hitting the Add Attributes For Current Render Type button. Maxwell renders spheres regardless of the render type set in Maya and uses a default radius of 1 when the radius attribute is not present.
Maya particles have a Blinn material by default which will be translated into a Maxwell approximation, but does not offer much control over the rendered look. It is recommended to assign a Maxwell material by right clicking the particle system in the viewport and selecting Assign New Material. In the following image, an iron material was applied on the particles:
It is not possible to use an emitter material on procedural particles. If you assign a material containing emitters on a particle system, Maxwell will print an error message and abort the render.
Maxwell can render translation motion blur for particles (multi-step blur is not supported). The position at the end of the exposure interval is obtained by multiplying the velocity of each particle by the shutter time and adding to the original position. An additional multiplier can be specified in the Maxwell Render group added by the plug-in in the Attribute Editor of the particle shape node.
Blur scale factor set to 1.
Same shutter time, blur scale factor set to 5.
If the particle system uses an instancer node, Maxwell will render the geometry instances. In this case, multi-step blur can be used and there are no material restrictions.