| Description: | The V-HACD library decomposes a 3D surface into a set of “near” convex parts.
Why do we need approximate convex decomposition?
Collision detection is essential for realistic physical interactions in video
games and computer animation. In order to ensure real-time interactivity with
the player/user, video game and 3D modeling software developers usually
approximate the 3D models composing the scene (e.g. animated characters, static
objects…) by a set of simple convex shapes such as ellipsoids, capsules or
convex-hulls. In practice, these simple shapes provide poor approximations for
concave surfaces and generate false collision detection.
Convex-hull vs. ACD
A second approach consists in computing an exact convex decomposition of a
surface S, which consists in partitioning it into a minimal set of convex
sub-surfaces. Exact convex decomposition algorithms are NP-hard and
non-practical since they produce a high number of clusters. To overcome these
limitations, the exact convexity constraint is relaxed and an approximate
convex decomposition of S is instead computed. Here, the goal is to determine a
partition of the mesh triangles with a minimal number of clusters, while
ensuring that each cluster has a concavity lower than a user defined
threshold.
The v-hacd-tools package contains command-line tools based on the V-HACD
library. Currently, this means TestVHACD; despite the name, this tool has
general utility beyond testing. |
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