for now subtype is not defined, but once we start parsing the metadata we can set texture inputs as FILEPATH
also, it takes relative strings and convert to absolute for all strings (which is arguably a good solution, but
should work for now)
Each BSDF node now has a Normal input, which can be used to set a custom normal
for the BSDF, for example if you want to have only bump on one of the layers in
a multilayer material.
The Bump node can be used to generate a normal from a scalar value, the same as
what happens when you connect a scalar value to the displacement output.
Documentation has been updated with the latest changes:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes
Patch by Agustin Benavidez, some implementation tweaks by me.
It's using the Ward BSDF currently, which has some energy loss so might be a bit
dark. More/better BSDF options can be implemented later.
Patch by Mike Farnsworth, some modifications by me. Currently it's not possible yet
to set a custom tangent, that will follow as part of per-bsdf normals patch.
This allows group nodes inside other group nodes in cycles and makes the
code more generic for all possible cases, like direct group
input-to-output links and unused group sockets.
Previous code tried to connect external nodes and internal group sockets
by following links until a "real" node input/output. This quickly
becomes complicated in corner cases as described above and can lead to
unexpected behavior when the group socket is of a different type than
the internal/external sockets, but that conversion is skipped.
The new code uses the concept of "proxy nodes" similar to what the new
compositor does. Each group socket is replaced with a proxy node with a
single input and output, to which other nodes in the same tree and
internal nodes can link to. After all groups have been expanded in the
graph, these proxy nodes are removed again, adding converter nodes if
necessary.
