Deborah R. Fowler
RBD | Bullet
Posted: 2013Updated: Dec 8 2023
Rigid Body Dynamics (RBD) are one of many simulations you can use in Houdini. To help guide the user I have categorized my RBD information into two sections related to the courses I teach.
- RBD Introduction - includes an overview of the solver, RBD Instanced Objects node and using the RBD for layout for example
- RBD Advanced (password required) covers microsolvers, customized fractures and customized constraints
Some reminders for both groups are SCALE / CACHING
/ PHYSICAL ATTRIBUTES / BULLET ASSUMPTIONS all matter
- SCALE MATTERS IN DYNAMICS! (Houdini measures in meters/kg/seconds - 1 unit is a meter (about 3 feet))
- When rendering on the renderfarm, cache (my instructions here) and the
documentation here
- Physical attributes of your RBD objects, including your collision objects, greatly influence the simulation
- Bullet was developed to be fast based on assuming things are convex, but there are ways around this ...
- Proxy geometry can be very useful in speeding up your sim times
- NOTE: In H16 the RBD Static Object has moved to the Collisions tab
- NOTE: In H18 RBD Bullet node in SOPS has been added for
convenience. The RBDbulletsolver is packaged
for convenience and it is important to be aware of both
- Reminder: DO NOT RENDER YOUR DOP NETWORK! Always bring the information out from your sim with a dop import (or if your dopnet is in sop level you can also use the Object Merge tab)
- New in H20 https://www.sidefx.com/docs/houdini20.0/news/20/rbd.html
- sticky collisions!
- curved glass
- New in H18 https://www.sidefx.com/docs/houdini18.0/news/18/rbd.html
- guided simulations - low res to high res sims or even animation - there is an excellent example file that can be found in the floating help (houdini running)
- the examples are not under "guided simulations" section but are under RBD Bullet Solver/Examples and is called GuidedRBDBulletSolver
- RBD bullet solver now works at the SOP level (Examples also under RDB Bullet Solver/Examples
- For convenience, SideFX example file here
- Steven Knipping's Applied Houdini RBD I for free (packed, transforms, vornoi, boolean, tools)
- New tools in H17.5 - see Fuat Yuksel's summary MucHUG April 2019
- presets for fracture - rbdmaterialfracture node (concrete, glass, wood)
- covers RBD contraints as well as Vellum Tetrahedral Fiber
Constraints
- RBD features update in H17 by Cameron White
- Check out the masterclasses on the bullet solver (H12)
- H13 Masterclass - Bullet Solver with Cameron White
- Also, if you have not
done so already, go thru the documentation on dynamics.
Be sure to include reading the "top ten" lists (see Subtopics/Learning Dynamics near the bottom of the page) that link to further pages. - http://bulletphysics.org/wordpress/
- http://fxguide.com/featured/art-of-destruction-or-art-of-blowing-crap-up