Why is there a difference in the way PCd calculates the distance from a plane to a point? Shouldn't a 2D distance from point to plane perpendicular to the plane be the same as a 3D distance from point to plane?

I understand the difference with the 2D will be larger the more skewed the plane is from the workplane. My current issue is not greatly skewed from the workplane & I'm only dealing with 3mm distance. How can the difference be as great as 0.4?

The plane is a X- plane, -2° to Z+. The points are offset from this plane 3mm & a plane construced of these points should be // to this plane. They were measured in Y-, the plane construced in Y- but the dimensions only come out reasonably close when dimensioned in Z+. I would think the 2D should be measured in Y- but the results come out 11.50.

Measured 2D in Z+, the top two pionts measure 2.97 & the bottom two measure 3.75.

Measured as 3D, they all come out around 3.30.

Measured in Y-, they come out 11.50.

I understand the difference with the 2D will be larger the more skewed the plane is from the workplane. My current issue is not greatly skewed from the workplane & I'm only dealing with 3mm distance. How can the difference be as great as 0.4?

The plane is a X- plane, -2° to Z+. The points are offset from this plane 3mm & a plane construced of these points should be // to this plane. They were measured in Y-, the plane construced in Y- but the dimensions only come out reasonably close when dimensioned in Z+. I would think the 2D should be measured in Y- but the results come out 11.50.

Measured 2D in Z+, the top two pionts measure 2.97 & the bottom two measure 3.75.

Measured as 3D, they all come out around 3.30.

Measured in Y-, they come out 11.50.

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