Does anyone know an easy way to project all the points in a group to a plane?

I have a group of points (a plane for example) and I want to project them all to a plane (simplest case == WORKPLANE). Is there some smart way to do it all at once (a.k.a. "the JEFMAN way") or is it only possible with a loop? I haven't found anything yet...

The object of this is to create a secondary tangent plane perpendicular to the primary by the following method:

- measure the secondary plane
- project all points up/down to the primary (WORKPLANE)
- construct a tangent plane from the original plane points + the projected points (guaranteed to be perpendicular to the primary as that is our projection direction)

As a follow-up question: How can I use an ARRAY variable in the same way as .HIT[...] in the construction of a tangent plane?

Parents

AndersI over 7 years ago

To give you an idea of what this is supposed to accomplish, here's [part of] my test program and some pictures. Just four points, creating a plane that is *not* perpendicular to the primary, projecting the four points and then creating a tangent plane (of all the points) that *is* perpendicular to the primary, touching the 'furthest' of the points of the plane:


PNT2       =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
            THEO/<38,0,-6>,<0,-1,0>
            ACTL/<38,-1,-6>,<0,-1,0>
            TARG/<38,-1,-6>,<0,-1,0>
            SNAP=NO
            REPORT VEC=<0,0,1>,UPDATE VEC=<0,0,1>
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
PNT3       =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
            THEO/<38,0,-29>,<0,-1,0>
            ACTL/<38,1,-29>,<0,-1,0>
            TARG/<38,1,-29>,<0,-1,0>
            SNAP=NO
            REPORT VEC=<0,0,1>,UPDATE VEC=<0,0,1>
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
PNT4       =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
            THEO/<180,0,-6>,<0,-1,0>
            ACTL/<180,-1,-6>,<0,-1,0>
            TARG/<180,-1,-6>,<0,-1,0>
            SNAP=NO
            REPORT VEC=<0,0,1>,UPDATE VEC=<0,0,1>
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO
PNT5       =FEAT/CONTACT/VECTOR POINT/DEFAULT,CARTESIAN
            THEO/<180,0,-29>,<0,-1,0>
            ACTL/<180,1,-29>,<0,-1,0>
            TARG/<180,1,-29>,<0,-1,0>
            SNAP=NO
            REPORT VEC=<0,0,1>,UPDATE VEC=<0,0,1>
            SHOW FEATURE PARAMETERS=NO
            SHOW CONTACT PARAMETERS=NO

PLN2       =FEAT/PLANE,CARTESIAN,OUTLINE,NO
            THEO/<109,0,-17.5>,<0,-1,0>
            ACTL/[COLOR=#FF0000]<109,0,-17.5>,<0,-0.9962406,-0.0866296>[/COLOR]
            CONSTR/PLANE,TANGENT,PNT2,PNT3,PNT4,PNT5,,
            MATH_TYPE/CONSTRAINED_MINMAX,BF

[COLOR=#008080]$ this is the part I want to accomplish as one (or a few) single commands, acting on the all the points at the same time. Just think of this on a scanned plane with thousands of points...

PNT6       =FEAT/POINT,CARTESIAN,NO
            THEO/<38,0,0>,<0,0,1>
            ACTL/<38,-1,0>,<0,0,1>
            CONSTR/POINT,PROJ,PNT2,
PNT7       =FEAT/POINT,CARTESIAN,NO
            THEO/<38,0,0>,<0,0,1>
            ACTL/<38,1,0>,<0,0,1>
            CONSTR/POINT,PROJ,PNT3,
PNT8       =FEAT/POINT,CARTESIAN,NO
            THEO/<180,0,0>,<0,0,1>
            ACTL/<180,-1,0>,<0,0,1>
            CONSTR/POINT,PROJ,PNT4,
PNT9       =FEAT/POINT,CARTESIAN,NO
            THEO/<180,0,0>,<0,0,1>
            ACTL/<180,1,0>,<0,0,1>
            CONSTR/POINT,PROJ,PNT5,[/COLOR]

[COLOR=#008080]$ end of problematic area[/COLOR]

PLN3       =FEAT/PLANE,CARTESIAN,OUTLINE,NO
            THEO/<109,0,-8.75>,<0,-1,0>
            ACTL/[COLOR=#0000FF]<109,-1,-8.75>,<0,-1,0>[/COLOR]
            CONSTR/PLANE,TANGENT,PNT2,PNT3,PNT4,PNT5,PNT6,PNT7,PNT8,PNT9,,
            MATH_TYPE/CONSTRAINED_MINMAX,BF

AndersI over 7 years ago in reply to AndersI

That won't work, as I don't have my Y direction yet - this is the secondary datum which shall decide the Y rotation and the Y zero. And, as you can see in the picture, the actual direction of the plane is not the correct direction to look for a MAX.

I agree that your method in most cases will be "good enough", but I'm trying to replicate "correct", i.e. the same results as putting the part on the plate (which of course is impossible, as I can't touch the full surface with a CMM, or even a scanner...).
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AndersI over 7 years ago in reply to AndersI

That won't work, as I don't have my Y direction yet - this is the secondary datum which shall decide the Y rotation and the Y zero. And, as you can see in the picture, the actual direction of the plane is not the correct direction to look for a MAX.

I agree that your method in most cases will be "good enough", but I'm trying to replicate "correct", i.e. the same results as putting the part on the plate (which of course is impossible, as I can't touch the full surface with a CMM, or even a scanner...).
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