63 - Antenna stretch blendShape with a curve info node (Cartoon character rigging series)

Much like the last tutorial we want to add the antenna stretchy blendShapes.

However we don't have a distance dimension tool to hook these to and further more the distance dimension tool doesn't actually give the full length of the antennas is we made one.

The distance tool only gives you the distance between two points but the antennas can be posed in some quite extreme bends (especially with the sine wave) so this means the stretch blendShape would only trigger depending on the distance between the two controls, not the length of the actual ribbon spine/antenna mesh.

To get the actual length what we can do is skin a curve to the antenna ribbon joints, then using some mel we can access the curve info node (basically information about the curve). This means as the curve deforms with the ribbon spine, we can get the actual length of the curve which will be the true length of the ribbon and use that to drive the stretch blendShape.

The same method can be used for the arms as-well but for the purpose of this tutorial i wanted to cover both as most arms will work fine with just using the distance tool as most arms work have the sine wave limbs.

NOTE: Again this will work but not as the rig is scales so in the next tutorial we will bypass both antenna and the arms at the same time so they work at any scale aswell.

Twitter:   / jamesdthompson  

Please leave any comments or questions below and ill try help as soon as possible.

Thanks for watching :)

Source files can be downloaded at:

https://dl.dropbox.com/u/30666061/JDT...