Design Scripting Documentation


	Intersection between planes


	Inputs:

two pairs of three points that define the planes


	Outputs:

an array of a vertex, vector pair of the intersection line

Implementation

01  function intersect_planeplane( pa, pb, pc, qa, qb, qc )
02    dim pn: pn = vector_normal( pa, pb, pc )
03    dim qn: qn = vector_normal( qa, qb, qc )
04  
05    dim dot: dot = vector_dot( pn, qn )
06    if( dot = 1.0 ) then
07      intersect_planeplane = vbnull
08      exit function
09    end if
10  
11    dim dp: dp = vector_dot( pa, pn )
12    dim dq: dq = vector_dot( qa, qn )
13  
14    dim dpn: dpn = vector_dot( pn, pn )
15    dim dqn: dqn = vector_dot( qn, qn )
16  
17    dim det: det = dpn * dqn - dot * dot
18  
19    if( det = 0.0 ) then
20      intersect_planeplane = vbnull
21      exit function
22    end if
23  
24    dim co: co = ( dp * dqn - dq * dot ) / det
25    dim ci: ci = ( dq * dpn - dp * dot ) / det
26  
27    intersect_planeplane = array(                    _
28      vertex_new(                                    _
29        co * pn( VERTEX_X ) + ci * qn( VERTEX_X ),   _
30        co * pn( VERTEX_Y ) + ci * qn( VERTEX_Y ),   _
31        co * pn( VERTEX_Z ) + ci * qn( VERTEX_Z ) ), _
32      vector_cross( pn, qn ) )
33  end function

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Page timestamp: { Feb. 2, 2006 }