CGAL users discussion list

[Daniel <>]

Hi everybody,

i have the following problem with projecting points on geometrical objects:

Given a point and a line in space, the projection of that point on the line
results in a point on that line, right? So the function "
line.has_on(line.projection(point)) " should become true. But in my program it
doesn't.

Furthermore i have a Plane_3 and a Triangle_3, both defined by the same points
in space. Now I project my point on the plane. Interestingly sometimes
plane.has_on(point) gives true sometimes false. Shouldn't it be always true?
Even weirder is, that I had situations where plane.has_on(point) is false, but
a the same time triangle.has_on(point) is true. If I haven't gotten anything
completely wrong, this should be impossible since the triangle actually lies 
on
the plane.

Also I would like to know, if there is any function in CGAL that calculates 
the
barycentric coordinates of a given point relative to a triangle.

I hope someone can help. Thanks in advance.

Daniel