Plane Class
dGeomID dCreatePlane (dSpaceID space,
dReal a, dReal b, dReal c, dReal d);
Create a plane geom of the given parameters, and return its ID. If space is nonzero, insert it into that space. The plane equation is
a*x+b*y+c*z = d
The plane's normal vector is (a,b,c), and it must have length 1. Planes are non-placeable geoms. This means that, unlike placeable geoms, planes do not have an assigned position and rotation. This means that the parameters (a,b,c,d) are always in global coordinates. In other words it is assumed that the plane is always part of the static environment and not tied to any movable object.
英文不好,看了半天才懂
a,b,c,d 四个参数
(a,b,c)是平面的法向量,一定要是1
d 面的位置(长度) 0的时候表示表穷大的面
void dMassTranslate (dMass *, dReal x, dReal y, dReal z);
Given mass parameters for some object, adjust them to represent the object displaced by (x,y,z) relative to the body frame.
相对于物体框架 (x,y,z)的位置