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Triangle/Ray Intersection

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4.6 | 5 ratings Rate this file 42 Downloads (last 30 days) File Size: 211 KB File ID: #33073 Version: 1.5
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Triangle/Ray Intersection

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29 Sep 2011 (Updated )

Fast vectorized triangle/ray intersection algorithm

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Description

Ray/triangle intersection using the algorithm proposed by Möller and
Trumbore (1997), implemented as highly vectorized MATLAB code.
The algorithm can work with one and two sided surfaces, as well as, with
infinite lines, rays (lines bounded on one side) and segments (lines bounded on
both sides).
 Input (all arrays in in Nx3, where N is number of vertices or rays):
   orig : ray's origin
   dir : ray's direction
   vert0, vert1, vert2: vertices of the triangle
 Output:
   Intersect - boolean array of length N
   t - distance from the ray origin to the intersection point in |dir|
   u,v - barycentric coordinates of the intersection point units
   xcoor - carthesian coordinates of the intersection point

In addition PointInsideVolume is 3D equivalent to 2D inpolygon function and can test if
array of points is inside or outside any volume defined by the surface grid.

Acknowledgements

Ray/Triangle Intersection inspired this file.

This file inspired In Polyhedron and Ray Shape Article Fex.Zip.

Required Products MATLAB
MATLAB release MATLAB 7.12 (R2011a)
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Comments and Ratings (12)
12 Jul 2016 Jamie Heather

Nice vectorised implementation with handy options for choosing between ray/line/segments and handling numerical precision issues - thanks!

15 Jun 2016 Jaroslaw Tuszynski

Reply to Murat: You might have to look into using "border" parameter. If it does not work can you construct a scenario that demonstrates the issue and email it to me

Comment only
14 Jun 2016 Murat

Murat (view profile)

Hi, the code is working well but it sometimes cannot handle with large incident angles. When the incident angle is around 90, it ignores triangles. Could you correct it?

Comment only
07 Jan 2016 Ehsan golk  
29 Oct 2014 Jeffrey

I'm having trouble with the many rays, many faces option. Lets say I have 11 faces and 5 rays. What resizing of the inputs needs to be done? Do I need to repmat all arrays to be of size 55x3?

Based on what I can tell it can handle:
- one ray, many faces
- many rays, one face
- many rays, many faces (but # of faces = # of rays)

But I think I am just missing something here.

19 Sep 2014 Jaroslaw Tuszynski

Reply to Nick: In many rays and many triangle case you still test for intersection of prearranged pairs and the return value informs you which ray/triangle pair intersected

Comment only
24 Mar 2014 Nick

Nick (view profile)

Very useful but when considering many rays and many triangles is there a way to find which ray has intersected which triangle?

Comment only
24 Mar 2014 Nick

Nick (view profile)

 
28 Aug 2013 Amilcar Torres

Excellent.. Really helpful!!!

12 Apr 2013 Ben

Ben (view profile)

Looks great. Downloaded and will try it later.

Comment only
06 Oct 2012 Jaroslaw Tuszynski

Re to Anton Semechko: This is a low level function which can be called with one ray and many faces, many faces and one ray or many faces and rays. It is quite simple to apply repmat function to the inputs.

Comment only
28 Feb 2012 Anton Semechko

why does the number of rays have to equal the number of faces? that's so inconvenient

Comment only
Updates
07 Oct 2011 1.1

Improvements to border handling

21 Mar 2013 1.2

correct treatment of 3x3 arrays as suggested by Andreas Weber

07 Jun 2013 1.4

documentation improvements and typo correction

03 Oct 2014 1.5

Major rewrite of the function with additional options and output variables. Also provided PointInsideVolume function

15 Jun 2016 1.5

correct description: no symbolic toolbox is needed

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