Why does direction ijk vector go away from point? I e the touch probe will hit a point going into part being measured but ijk is reported as coming from point on part.
I'm not a cmm programmer. Work in quality appreciate any wisdom. Please excuse my ignorance. Thankyou!
Just to add to the other post, the vector of a point describes the point itself. It's not a instruction on how to measure or probe the point. So the vector of a point describes how it is facing relative to the surface that it's on. If a point is on top of a part, then it's facing the Z plus direction, so it's vector is 0,0,1.
By definition, the vector is perp to the surface, on the free side of the material.
On a CAD, it's the definition, on a mesh also.
If you look a numerical movie, the color of the mesh is done on the external surface.
A CMM just uses the opposite of it to measure, so the spheritical tip touch the part on the tangent of the surface, and the tip radius is correctly compensated.