Depending on where the point is, it could be closest to a vertex, an edge, or a plane. You need to figure out which it is before you can calculate the distance.

To find the distance from a line to a point, where the point is p, and the line is defined by vertex1 and vertex2:

va = vertex2 - vertex1;

vb = p - vertex1;

distance = Length(vb-va*(va*vb)/LengthSquared(va));

(va*vb is dot product)

Ok thank you all for the help and formulas. I''m gonna try what Basiror suggested, it''s simple enough and it should work. If it doesn''t then I guess I''ll be back here

i think i found an easier method


check if the point projected onto the plane is inside the polygon if not

create a plane perpendicular to the plane
generate its normal

project the point onto each plane and find out which projected point has the closes distance to he original point

then take this point and project it onto the plane and check whether it lies on an edge

if it doesn t project the already projected point onto the other planes which you have generated and check again

1st projected point latest projected point

and choose the edge/plane with the shortest distance


now the point should be the vertex of one of your corners

just get the distance between the original point and the result of the 1st projection or if the 1st failed of the second


and you don t need more than 2 projections to find the shortest result




this works precise and very fast

good luck

i am sorry you may not perform the second to-plane projection

if the first fails get the distance between the vertices of the edge and take the shorter one

Ok Thanks. I''m gonna try your technique tonight and come back.(I don''t have access to a pc on week-ends)

It worked! Thanks a lot..