2013-05-02

Maya wrap deformer tips


Attributes:
  • After creating a wrap deformer the driver surface gets a dropoff and smoothness attribute. Usually the user can expect these attributes to be in the deformer ChannelBox/AttributeEditor. This has been changed for the wrap deformer for a case were there is one driver on multiple shapes, so the smoothness attribute gets connected to each wrap deformer. The smoothness only works with Falloff Mode: Volume and Exclusive Bind: off. As the name says it can help create smooth deformations. On the downside it moves unaffected neighbors of deformed vertices in the opposite direction, so that may be a reason not to use smoothness for some cases.
  • When enabled Exclusive Bind improves performance a lot, but may lead to bad deformation. Works especially well when driver and driven have a similar resolution. I used this setting a lot in the past.
  • I usually use Falloff Mode: Surface for smooth results, probably because my driver and driven object usually have a similar shape. The smoothness attribute requires Volume mode thou.
  • maxDistance 0.0 disables maxDistance
Use cases:
  • Deform highres geometry with easier to rig/cloth-simulate low-res geometry. For this case my tip is to output the lowres mesh into a separate mesh node and smooth/subdivide that and then use this highres version of the lowres mesh as wrap deformer driver on the actual highres mesh. The result is surprisingly fast when using exclusive bind etc and allows for much better deformation than using the wrap deformer the normal way and trying to adjust the wrap deformer attributes, which can never work properly (it's a non-barycentric binding) and gets really slow. As with many deformers in Maya, they are not very functional, but they are fast, so when making these procedural deformations you can compensate for the lack of features.
  • When the driving mesh just has a skinCluster I prefer to copy the skinCluster and weights to the highres, because it calculates faster than a wrap deformer and you also have the option of tweaking the weights further.
  • Use as partial blendshape, to be able to work on local area and with those patches drive the final one-piece mesh. Edit membership has to be used to avoid double transformation. Not a user friendly workflow. Exclusive Bind can be used to greatly improve speed (if meshflow is similar).
Example: