Day09: Tutorials Part 03 (Mantra)

Continued the tutorials, this time it covers mantra render engine.
It talked about the different engines that is available.

• Micropolygon
• Raytracing
• Micropolygon Physically Base Rendering
• Physically Base Rendering

The render engines in Houdini are very efficient it's know to render displacement, motion blur etc faster compared to many other engines.

Also talked about render view and IPR, in the render view we could specify to use which ever mantra node.

A good thing to take note is that IPR will run in the background unless it is killed. So it will eat up memory, killing it before some heavy rendering helps.


Did a simple test rig and drive the motion through CHOPS and expressions.

Issues

• The deformation around the tip/neck, probably due to not enough resolution.
• The animation driven by chops and expressions are very predictable.
• When my lower controls moves it pulls the head off position, making stretchy bones might do the trick. 

Updates
Managed to implement stretchy bones.

Since I'm using the curve to drive the bones, first I needed to find the length of the curve. Using the arclen() expression I was able to get the length of the curve.

Bones in Houdini have this parameter "Bone length", it defines the length of the bone in Z axis. By dividing the length of the curve to the number of bones, whenever the curve goes beyond the initial length, the bone length will recalculates and make it stretchable.

Resource:
http://www.darksuit.com/tutorials/StretchSpine.html

Rigging controls

Test key-frame animation

There is a certain flipping issues if the movement is too big or hit certain threshold.

Doing my best at animating it...