Hye everyone,

I read the sticky node inside the simple biped hda and i have some questions about.

1 - “Nulls objects are optimized to be displayed more efficiently.”
What this that mean exactly?
because they are based on bgeo file ?

2 - “Each level of asset nesting adds a performance hit.”
What matrix computation behind this type of setup ?


Thanks.

nulls and bones have been optimized to display much faster than before…
in a typical character rig you might have 100+ bones and 100's of nulls…so instead of loading all of these objects Houdini uses a kind of instancing for bones and nulls…
but it's still a good idea to use as few bones/nulls as is reasonable for your HDA.
as for nested hierarchies…
having parameters on the top level of a character HDA drive parameters on a sub-HDA, that drive parameters on a node inside the sub-HDA is slower than having the top level parameter drive the node directly…

Thanks Arctor.

Hi , I have a problem about this HDA too. Why all bones are interleaved with null object ,even if eye bones that does not need handle directly from viewport ?
Doesn't these null object hierarchy eat performance ?

re bone/null combinations

it's a pretty standard workflow to use nulls to control bones in situations like this rather than drive bones directly…in most cases the performance hit his very small - smaller now with the bone/null optimizations…

arctor
re bone/null combinations

it's a pretty standard workflow to use nulls to control bones in situations like this rather than drive bones directly…in most cases the performance hit his very small - smaller now with the bone/null optimizations…

I like this rig, it's simple and flat. But I don't know how to fit this rig to my own character geometry simply. Bone/null combination seemed to hard adjust position. I must adjust every bone length and align all null to it's parent bone's tip. This is not simple as use bone tool to adjust bone pose. Maybe I have not got right method ?

no, this isn't the right method.
adjusting an existing rig to new geometry is always a huge pain - and should be avoided.
This is what auto-rigs are for

while Houdini does ship with an auto-rig system I'd advise against using it - it will build you a rig but it will be slow and very difficult to customize.
There are plans to replace this system in a future release.

what you can do now is build a new rig for your character and use the simple biped rig (male and female are the same) as a guide - this way you'll learn a bit about rigging in Houdini and easily be able to test out your own ideas - like removing those nulls - and see the results.
It might sound like this will take longer but actually it will likely take the same amount of time.