The basic idea of animation of a rigid body motion is the same as that of animation of a moving point discussed in Section 2 and 3. The only difference is that in the case of a rigid body motion the object to draw and erase is a three-dimensional shape.
Let us make an animation of a moving block as an example. This can be done based on the script developed in Section 6 for drawing a block shape in a general configuration.
First, in order to make the script concise let us define a function that returns patches data needed to draw a block shape by plot3d as in Code 1.
function patches = calcBlock(r, R, Lx, Ly, Lz)
// Return patches data of a block geometry
// Vertices
vertices_0 = [
0, 0, 0; // #1
Lx, 0, 0; // #2
0, Ly, 0; // #3
0, 0, Lz; // #4
Lx, Ly, 0; // #5
0, Ly, Lz; // #6
Lx, 0, Lz; // #7
Lx, Ly, Lz]; // #8
vertices = transver(vertices_0, r, R);
// Faces
faces = [
1, 2, 5, 3; // #1
1, 3, 6, 4; // #2
1, 4, 7, 2; // #3
4, 7, 8, 6; // #4
2, 5, 8, 7; // #5
3, 6, 8, 5]; // #6
// Patches
patches = genpat(vertices, faces);
endfunction
Using the calcBlock() function in Code 1, we can rewrite the script developed in Section 6 for drawing a block shape in a general configuration concisely as in Code 2 below.
// make_block.sce
clear; xdel(winsid());
exec('eulerXYZ.sci', -1);
exec('transver.sci', -1);
exec('genpat.sci', -1);
exec('calcBlock.sci', -1);
// Reference position
r = [1; 1; 1];
// Reference orientation
R = eulerXYZ(-%pi/3, 0, %pi/6);
// Side lengths
Lx = 0.15;
Ly = 0.05;
Lz = 0.30;
// Patches
patches = calcBlock(r, R, Lx, Ly, Lz);
// Draw patches
h_fig = figure;
h_fig.background = 8;
h_pat = plot3d(patches.x, patches.y, patches.z);
h_pat.color_mode = 4;
h_pat.foreground = 1;
h_pat.hiddencolor = 4;
// Axes settings
xlabel("x"); ylabel("y"); zlabel("z");
h_axes = gca();
h_axes.isoview = "on";
h_axes.box = "off";
h_axes.rotation_angles = [63.5, -127];
h_axes.data_bounds = [0.8, 0.9, 0.8; 1.3, 1.4, 1.3];
xgrid;
