Hi All,
In the process of rewriting the FlightGear elevation code,
I have tried to make it generic enough to be of general use
to the PLib community.
If anyone is interested in BETA testing a collection of routines
that will gather info about the intersection of a directed line
segment and a SSG graph, drop me a line.
Info gathered for each point of intersection:
pointer to intersected leaf
index of intersected face in said leaf
coordinates of intersection point
normal to face at intersection point
Example Usage:
ssgBranch *scene;
sgVec3 line_orig, line_dir;
// declare it
FGHitList hit_list;
// this is all you have to do :-)
hit_list.Intersect( scene, line_orig, line_dir ) ;
// Things you can do
int closest = -1;
float dist, min_dist = FLT_MAX;
for ( int i=0; i<hit_list.num_hits(); i++ )
{
ssgEntity *leaf = hit_list.get_entity(i);
int tri_index = hit_list.get_face(i);
sgVec3 this_point = hit_list.get_point(i);
sgVec3 this_normal = hit_list.get_normal(i);
dist = sgDistanceSquaredVec3( line_orig, this_point);
if( dist < min_dist ) {
min_dist = dist;
closest = i;
}
short i1, i2, i3;
leaf->getTriangle( tri_index, &i1, &i2, &i3 );
float intersected_tri[3][3];
sgCopyVec3(intersected_tri[0], leaf->getVertex(i1);
sgCopyVec3(intersected_tri[1], leaf->getVertex(i2);
sgCopyVec3(intersected_tri[2], leaf->getVertex(i3);
}
Cheers
Norman Vine
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