pvdl@tnoibbc.UUCP (Peter van de Leur) (02/09/90)
I am looking for a solution to the following problem:
I have a volume bounded by 6 planes that are not parallel nor perpendicular to
one another (this element probably has a name, but I am not aware of it) .
I have also got a straight line running in an arbitrary direction.
I need to know :
1. whether the line crosses the volume
2. If it crosses, what is the length of the cross-section.
The literature that I have access to gives me either very very basic
information or only a general guideline how to solve this kind of problem.
Does anyone have a solution ready? I think that the finite-element post-
processor writers must have solved it, e.g. for contour generating; perhaps
also the ray-tracer people did it.
Please mail any suggestions. As I have understood during my enquiries, more
people are interested, so I will certainly post any substantial results.
--
Peter van de Leur : TNO - IBBC USENET : pvdl@tnoibbc
: PO-box 49 UUCP : ..!hp4nl!tnoibbc!pvdl
: 2600 AA Delft
: the Netherlands VOICE : +31 15 842313root@cca.ucsf.edu (Systems Staff) (02/13/90)
In article <1393@tnoibbc.UUCP>, pvdl@tnoibbc.UUCP (Peter van de Leur) writes: > > I am looking for a solution to the following problem: > > I have a volume bounded by 6 planes that are not parallel nor perpendicular to > one another (this element probably has a name, but I am not aware of it) . I take it you intend this to be a distorted cube? You would need to constrain the planes additionally to ensure this. The conditions given could lead to a skewed hexagonal cylinder which would be unbounded. In any case, the volume is defined by a set of linear inequalities which say which side of each plane the volume lies on. > I have also got a straight line running in an arbitrary direction. And this part is defined by linear equations. > I need to know : > 1. whether the line crosses the volume > 2. If it crosses, what is the length of the cross-section. Linear equations and linear inequalities? Looks like a small linear programming problem from here. Is there something I'm missing? Thos Sumner Internet: thos@cca.ucsf.edu (The I.G.) UUCP: ...ucbvax!ucsfcgl!cca.ucsf!thos BITNET: thos@ucsfcca U.S. Mail: Thos Sumner, Computer Center, Rm U-76, UCSF San Francisco, CA 94143-0704 USA I hear nothing in life is certain but death and taxes -- and they're working on death. #include <disclaimer.std>