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Remove mjOption.collision and associated option/collision attribute.

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PiperOrigin-RevId: 566427090
Change-Id: I6e5873b8db707586820b17b53c7ab4bbff0f0b2b
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Yuval Tassa
2023-09-18 15:14:33 -07:00
committed by Copybara-Service
parent 9902b73502
commit 9cf1f6eba4
18 changed files with 108 additions and 208 deletions
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doc/computation.rst
+10 -17
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@@ -1466,25 +1466,18 @@ others can be pruned quickly without a detailed check. MuJoCo has flexible mecha
checked in detail. The decision process involves two stages: generation and filtering.
Generation
First we generate a list of candidate geom pairs in one of two ways: "pair" or "dynamic". The user can also specify
"all" which merges both sources (and is the default). This is done via the setting ``mjModel.opt.collision``. "Pair"
refers to an explicit list of geom pairs defined with the :ref:`pair <contact-pair>` element in MJCF. It gives the
user full control, however it is a static mechanism (independent of the spatial arrangement of the geoms at runtime)
and can be tedious for large models. It is normally used to supplement the output of the "dynamic" mechanism. Dynamic
generation works with bodies rather than geoms; when a body pair is included this means that all geoms attached to
one body can collide with all geoms attached to the other body.
First we generate a list of candidate geom pairs in two ways:
The body pairs are generated via broad-phase collision detection based on a modified sweep-and-prune algorithm. The
modification is that the axis for sorting is chosen as the principal eigenvector of the covariance matrix of all geom
centers - which maximizes the spread. Then, for each body pair, a mid-phase collision detection using a static
bounding volume hierarchy (a BVH binary tree) of axis-aligned bounding boxes (AABB) is performed. Each body is
equipped with an AABB tree of its geoms, aligned with the body inertial or geom frames for all inner or leaf nodes,
respectively.
- Using predefined geom pairs, specified with the :ref:`contact-pair <contact-pair>` element. This mechanism is
independent of the spatial arrangement of the geoms at runtime.
- Generating candidate geom pairs by examining the runtime locations of bodies. First, a sweep-and-prune broadphase
collision stage prunes bodies that cannot collide. Then, a mid-phase collision stage further prunes geom pairs from
remaining body pairs using a static Bounding Volume Hierarchy (a binary tree) of axis-aligned bounding boxes.
Each body is equipped with an AABB tree of its geoms, aligned with the body inertial or geom frames for all inner
or leaf nodes, respectively.
- The user can also explicitly exclude certain body pairs using the :ref:`exclude <contact-exclude>` element.
Finally, the user can explicitly exclude certain body pairs using the :ref:`exclude <contact-exclude>` element
in MJCF. Exclusion is applied when "dynamic" or "all" are selected, but not when "pair" is selected. At the end of
this step we have a list of geoms pairs that is typically much smaller than :math:`n (n-1)/2`, but can still be
pruned further before detailed collision checking.
These two lists are then merged.
Filtering
Next we apply four filters to the list generated in the previous step. Filters 1 and 2 are applied to all geom pairs.