collisionMesh

Create convex mesh collision geometry

Description

Use collisionMesh to create a collision geometry as a convex mesh using a list of 3-D vertices relative to a frame of choice.

Creation

Syntax

MSH = collisionMesh(Vertices)

MSH = collisionMesh(___,Pose=pose)

Description

MSH = collisionMesh(Vertices) creates a convex mesh collision geometry from the list of 3-D Vertices. The vertices are specified relative to a frame of choice (collision geometry frame). By default, the collision geometry frame collocates with the world frame.

MSH = collisionMesh(___,Pose=pose) sets the Pose property of the mesh to pose, relative to the world frame.

Properties

Vertices — Vertices

N-by-3 matrix

Vertices of a mesh, specified as an N-by-3 matrix, where N is the number of vertices. Each row of Vertices represents the coordinates of a point in 3-D space. Note that some of the points can be inside the constructed convex mesh.

Data Types: double

Pose — Pose

eye(4) (default) | real-valued 4-by-4 matrix | se3 object

Pose of the collision geometry relative to the world frame, specified as a 4-by-4 homogeneous matrix or an se3 object. You can change the pose after you create the collision geometry.

Note

Note that when the pose is specified as an se3 object, the Pose property stores the pose as a numeric 4-by-4 matrix.

Data Types: single | double

Object Functions

checkCollision	Check if two geometries are in collision
fitCollisionCapsule	Fit collision capsule around collision geometry
show	Show collision geometry

Examples

Create and Visualize Mesh Collision Geometry

Create an array consisting of the coordinates of ten points randomly chosen on the unit sphere. For reproducibility, set the random seed to the default value.

rng default
n = 10;
pts = zeros(n,3);
for k = 1:n
    ph = 2*pi*rand(1);
    th = pi*rand(1);
    pts(k,:) = [cos(th)*sin(ph) sin(th)*sin(ph) cos(ph)];
end

Create a convex mesh collision geometry from the array. Visualize the collision geometry.

m = collisionMesh(pts);
show(m)

Create a second array similar to the first, but this time consisting of 1000 points randomly chosen on the unit sphere.

n = 1000;
pts2 = zeros(n,3);
for k = 1:n
    ph = 2*pi*rand(1);
    th = pi*rand(1);
    pts2(k,:) = [cos(th)*sin(ph) sin(th)*sin(ph) cos(ph)];
end

Create and visualize a mesh collision geometry from the array. Observe that choosing more points on the sphere results in a sphere-like mesh.

m2 = collisionMesh(pts2);
show(m2)

Create an array consisting of the coordinates of the eight corners of a cube. The cube is centered at the origin and has side length 4.

cubeCorners = [-2 -2 -2 ; -2 2 -2 ; 2 -2 -2 ; 2 2 -2 ;...
    -2 -2 2 ; -2 2 2 ; 2 -2 2 ; 2 2 2]

cubeCorners = 8×3

    -2    -2    -2
    -2     2    -2
     2    -2    -2
     2     2    -2
    -2    -2     2
    -2     2     2
     2    -2     2
     2     2     2

Append cubeCorners to pts2. Create and visualize the mesh collision geometry from the new array. Because the cube contains the sphere, the sphere points that are interior to the cube are disregarded when creating the geometry.

pts3 = [pts2;cubeCorners];
m3 = collisionMesh(pts3);
show(m3)

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2019b

R2023b: collisionMesh supports specifying pose at construction

You can now specify the Pose property of collisionMesh at object construction.

R2023a: Pose property supports se3 transformation object

You can now specify the Pose property of collisionMesh as an se3 transformation object.