Appleseed currently supports a set of powerful predefined materials, brdfs, edfs and surface_shaders. Mayaseed takes a set of entity definitions name
appleseedEntityDefs.xml generated by appleseed.cli and uses them to create shading node templates in Maya that mirror their appleseed counterparts.
All mayaseed materials must have an ms_material at their root. Create an ms_material by choosing
Mayaseed > Create Material.
As Maya has no notion of explicit front and back materials, the ms_material has slots for front and back bsdfs, edfs and surface_shaders.
Once you have your ms_material you then need to connect up some other shading nodes. To create shading nodes chose
Mayaseed > Create Bsdf etc.
It's worth noting that in appleseed an attribute of a material or shading node takes other shading node entities as arguments rather than attributes of other shading nodes, so you might connect
bsdf_1 -> material_1.bsdf. This is similar to Maya where you might connect
shading_node_1.outColor -> material_1.color. Because of this the attributes you use to connect up materials and shading nodes in Maya can be arbitrary; for example, connecting
my_shading_node.outColor -> my_ms_material.front_bsdf_color will have the same effect as
my_shading_node.message -> my_ms_material.front_bsdf_color.
Below is a typical shading network using an ms_material.
Note: Maya has a limitation with render nodes that have attributes generated at runtime. This means that when you graph a node's connections you may not see the whole hierarchy. As a work-around, graph the connections of a node, then select all the connections that are shown and graph connections again. K eep doing this until you can see all the nodes in the hierarchy.
When you first create a shading node you might find that it has no attributes shown. The attributes are there; you just need to expand the
Extra Attributes section to see them.