My First Houdini Plugin: An World-Only Object Node

   1441   0   1
User Avatar
Member
63 posts
Joined: Aug. 2013
Offline
I wrote this node so that I had an easier time with using an object input/output hierarchy where I wanted the object connections to be “in spirit alone,” so to speak. Basically I was having problems with simply using “ignore parent” and “child compensate” attributes, so I finally resorted to delving into the HDK, and found that controlling the transformation matrix in a OBJ_Node plugin is a whole lot easier than with Maya's MFnTransform/MFnTransformationMatrix API.

Basically, if you don't want to send or receive transformation matrix data, you just have to return an identity matrix for both the applyOutputTransform [www.sidefx.com] and applyInputDependentTransform [www.sidefx.com] overrides.

As a result, I can now use the objects in my hierarchy to control not only the locations of points for a polyWire node, but I can also apply a non-uniform rotation and/or scale without affecting the child/sibling nodes and without loosing the hierarchy network! I suppose there's a way to do this with assets, subnets, chopnets, etc…but as I'm still basically a novice to Houdini, this seems to be the least painful approach.

I'm not yet sure what other benefits such a node could have, but I'm open to suggestions. I can't compile for Win/Mac, but here's the source/scene/Linux DSO if anyone's interested…

(PS: the emb-notation stands for Escher-Muybridge: They are both names I decided to use for my fantasy Rigging and Animation software, but I incorporated them here as well, since I couldn't figure out any other convention to use for this project…)

Attachments:
embWireframe_demo.png (431.2 KB)
2018-09-07_11-53.png (24.0 KB)
embWireframe_050.hipnc (190.4 KB)
OBJ_embWorld.tar.gz (316.8 KB)

  • Quick Links