GJK算法matlab
时间: 2023-11-13 17:54:02 浏览: 138
Fast 3D Collision Detection -- GJK 算法:GJK 凸面 3D 物体碰撞检测算法。-matlab开发
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GJK算法是一种用于计算两个凸多边形之间最小距离的算法。在Matlab中,可以使用以下代码实现GJK算法:
```matlab
function [distance, simplex] = gjk(A, B)
% 初始化
d = [1; -1];
v = A(:, 1) - B(:, 1);
simplex = v;
% 迭代
while true
% 计算最靠近原点的点
[~, i] = max(d .* dot(simplex, repmat(-v, 1, size(simplex, 2))));
% 计算下一个点
v = A(:, i) - B * simplex(:, i);
% 判断是否相交
if dot(v, simplex(:, i)) <= 0
distance = norm(simplex(:, i));
break;
end
% 更新simplex
simplex = [simplex, v];
% 判断是否包含原点
if contains_origin(simplex)
distance = 0;
break;
end
end
end
function contains = contains_origin(simplex)
% 判断simplex是否包含原点
switch size(simplex, 2)
case 2
contains = contains_origin_2d(simplex);
case 3
contains = contains_origin_3d(simplex);
case 4
contains = contains_origin_4d(simplex);
end
end
function contains = contains_origin_2d(simplex)
% 判断2D simplex是否包含原点
a = simplex(:, 2) - simplex(:, 1);
b = -simplex(:, 1);
ao = -simplex(:, 1);
if dot(a, ao) <= 0
contains = false;
else
ab = a / norm(a);
ap = b - dot(b, ab) * ab;
contains = dot(ap, ao) <= 0;
end
end
function contains = contains_origin_3d(simplex)
% 判断3D simplex是否包含原点
a = simplex(:, 3) - simplex(:, 1);
b = simplex(:, 2) - simplex(:, 1);
c = cross(a, b);
d = -simplex(:, 1);
if dot(c, d) <= 0
contains = false;
else
ab = cross(c, b);
ac = cross(a, c);
if dot(ab, d) <= 0
contains = false;
elseif dot(ac, d) <= 0
contains = false;
else
contains = true;
end
end
end
function contains = contains_origin_4d(simplex)
% 判断4D simplex是否包含原点
a = simplex(:, 4) - simplex(:, 1);
b = simplex(:, 3) - simplex(:, 1);
c = simplex(:, 2) - simplex(:, 1);
d = cross(c, cross(a, b));
e = -simplex(:, 1);
if dot(d, e) <= 0
contains = false;
else
abc = cross(a, b);
acd = cross(a, d);
adb = cross(d, b);
if dot(abc, c) * dot(abc, e) <= 0
contains = false;
elseif dot(acd, a) * dot(acd, e) <= 0
contains = false;
elseif dot(adb, b) * dot(adb, e) <= 0
contains = false;
else
contains = true;
end
end
end
```
其中,A和B分别表示两个凸多边形的顶点坐标,distance表示两个凸多边形之间的最小距离,simplex表示GJK算法中的simplex。
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