The flex-SDF algorithm uses the same logic as mesh-SDF. Previous to this change, the flex was instead colliding with the convex hull of the mesh generated automatically with marching cubes from the SDF.
PiperOrigin-RevId: 876420302
Change-Id: I3bf6552b6b8e108ba4c4209bbcf10fe5f2b2fd90
This change introduces a filter for flex-related contacts, ensuring that no more than mjMAXCONPAIR contacts are kept for each geom-flex, flex-flex, flex internal, and flex self-collision pair. The contacts are sorted using farthest-point sampling:
- Starts with the deepest penetrating contact
- Iteratively selects the contact farthest from already-selected contacts
- Produces a spatially distributed set of contacts
PiperOrigin-RevId: 872593388
Change-Id: I50b233a0dc66da6a297852c258ba514f131c8f23
These flexes use only 24 DOFs (3 per vertex of the bounding box), while colliding with the full high resolution mesh.
On an 8x8x8 cube, the performance using DOFs at all vertices is
```
Simulation time : 18.74 s
Steps per second : 533
Realtime factor : 0.53 x
Time per step : 1874.4 µs
Contacts per step : 114.88
Constraints per step : 3322.51
Degrees of freedom : 1536
```
With the new implementation, it is the following:
```
Simulation time : 1.82 s
Steps per second : 5507
Realtime factor : 5.51 x
Time per step : 181.6 µs
Contacts per step : 38.84
Constraints per step : 155.36
Degrees of freedom : 24
```
PiperOrigin-RevId: 721008829
Change-Id: I833df027527db578d86667cc4b24295bcf6f7d22
These functions names and argument ordering are more consistent with the rest of the API.
PiperOrigin-RevId: 643788290
Change-Id: I783eda8021b80b82098e23ed95669b102bb82508
That change removed some spurious contacts returned by mjc_BoxBox, but also removed some desirable contacts that occur during very deep penetration of two boxes (when one box is completely inside another box). This is now fixed.
PiperOrigin-RevId: 591036252
Change-Id: I84b51f2179fd6fe29618a4e908e86934c6fc6941
The box-box collider sometimes outputs bad contact points which are far outside one of the two boxes. This happens at configurations which are very rare numerically, but rare configurations (e.g. perfect box alignment) are often induced by the designer and the physics, making them actually not-so-rare.
Since the box collision functions are very difficult to understand, we circumvent the issue by extending the post processing code to detect and remove such contacts.
PiperOrigin-RevId: 589178197
Change-Id: I82b8a888ef04f9196111c960757e3314d0ab6d8e
- Fixed bug in timing of kinematics, was under-reported.
- Moved timing of inertia and collision into respective functions, in preparation for multi-threading.
- Detailed profiling in `testspeed` is always on, removed command-line flag.
- Improved `testspeed` self-documentation.
PiperOrigin-RevId: 571989548
Change-Id: If0e3cc17f6f3511b98fc36339f406a19968a9361
This results in approximately 4-5% speedup in collision detection for particle.xml.
PiperOrigin-RevId: 562526634
Change-Id: Ia6487b1908618064d858bac484fe6861ed37a402
At the leaves of the midphase trees in `mj_collideTree`, a bounding sphere test is performed. The margin was incorrectly set to zero instead of reading it from `geom_margin`.
PiperOrigin-RevId: 559782262
Change-Id: Icfceb8445bbf6977582e0061566d7bd4def2f0ae
Yuval Tassa