# # This file employs surface ray intersector (srinter) to compute arbitrary # precise mapping in the parametric space of a given surface to a rectangle # projection in space of a surface region. # # This module can be used, for example, for texture mapping computation # of symbols and marks on planes and ships. Herein, we demonstrate its use # on parts of the 58 model (b58.irt). # # Gershon Elber, June 1995. # Param = PARAM_UNIFORM; NumCols = 16; NumRows = 4; Postfix = "Unif16x4"; # # Blends two points into a point in between. # PPBlend = function( Pt1, Pt2, t ): return = coerce( Pt1 * t + Pt2 * (1 - t), point_type ); # # Intersects the given surface with a line swept in dir Dir from Pt1 to Pt2 # The intersection is approximated using a cubic Bezier curve. # SrfLineInter = function( Srf, Pt1, Pt2, Dir, Param, NumSegs ): Pta : Ptb : Ptc : Ptd : Crv : Crvs : c : i : Pta = srinter( Srf, Pt1, Dir ): Ptb = srinter( Srf, PPBlend( Pt1, Pt2, 2 / 3 ), Dir ): Ptc = srinter( Srf, PPBlend( Pt1, Pt2, 1 / 3 ), Dir ): Ptd = srinter( Srf, Pt2, Dir ): Crv = bsp2bzr( cinterp( list( Pta, Ptb, Ptc, Ptd ), 4, 4, Param, false ) ): Crvs = nil(): for ( i = 1, 1, NumSegs, c = cregion( Crv, (i - 1) / NumSegs, i / NumSegs ): color( c, i ): snoc( c, Crvs ) ): return = Crvs; # # Sample the surface at a rectangle as well as three interior curves. # MakeBezierCurves = function( Srf, Pt1, Pt2, Pt3, Pt4, Dir, Param, n, m ): Rows : Cols : i : Rows = nil(): for ( i = 0, 1, n, snoc( SrfLineInter( Srf, PPBlend( Pt4, Pt1, i / n ), PPBlend( Pt3, Pt2, i / n ), Dir, Param, m ), Rows ) ): Cols = nil(): for ( i = 0, 1, m, snoc( SrfLineInter( Srf, PPBlend( Pt2, Pt1, i / m ), PPBlend( Pt3, Pt4, i / m ), Dir, Param, n ), Cols ) ): return = list( Rows, Cols ); ############################################################################# # # Back part of the fuselage: # c1 = cbspline( 3, list( ctlpt( P3, 1, 2.5, 0.0, -0.1 ), ctlpt( P3, 0.707, 1.77, 0.283, -0.071 ), ctlpt( P3, 1, 2.5, 0.4, 0.0 ), ctlpt( P3, 0.707, 1.77, 0.283, 0.566 ), ctlpt( P3, 1, 2.5, 0.0, 0.8 ), ctlpt( P3, 0.707, 1.77, -0.283, 0.566 ), ctlpt( P3, 1, 2.5, -0.4, 0.0 ), ctlpt( P3, 0.707, 1.77, -0.283, -0.071 ), ctlpt( P3, 1, 2.5, 0.0, -0.1 ) ), list( 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 4 ) ) * trans( vector( 0.0, 0.0, 0.0 ) ); color( c1, red ); c2 = c1 * scale( vector( 1.05, 1.05, 1.05 ) ) * trans( vector( 0.3, 0.0, 0.0 ) ); color( c2, red ); c3 = c1 * scale( vector( 0.95, 0.95, 0.95 ) ) * trans( vector( 1.7, 0.0, -0.02 ) ); color( c3, red ); c4 = circle( vector( 0.0, 0.0, 0.0 ), 0.35 ) * roty( 90 ) * trans( vector( 5.0, 0.0, 0.2 ) ); color( c4, red ); c5 = c4 * trans( vector( 0.2, 0.0, 0.0 ) ); color( c5, red ); c6 = circle( vector( 0.0, 0.0, 0.0 ), 0.3 ) * roty( 90 ) * trans( vector( 10.5, 0.0, 0.2 ) ); color( c6, red ); c7 = circle( vector( 0.0, 0.0, 0.0 ), 0.01 ) * roty( 90 ) * trans( vector( 11.0, 0.0, 0.25 ) ); color( c7, red ); fuseBack = sFromCrvs( list( c1, c2, c3, c4, c5, c6, c7 ), 3 ); color( fuseBack, red ); view_mat = rotx( -90 ) * trans( vector( -3.0, 0.0, 0.0 ) ) * scale( vector( 0.5, 0.5, 0.5 ) ); Resolution = 100; FuseParamSpace = poly( list( point( 0, 0, 0 ), point( 4, 0, 0 ), point( 4, 5, 0 ), point( 0, 5, 0 ), point( 0, 0, 0 ) ), true ); color( FuseParamSpace, yellow ); Pt1 = point( 2.7, 5, -0.05 ); Pt2 = point( 4.0, 5, -0.05 ); Pt3 = point( 4.0, 5, 0.7 ); Pt4 = point( 2.7, 5, 0.7 ); Dir = vector( 0, -1, 0 ); view( list( fuseBack, Pt1, Pt2, Pt3, Pt4 ), on ); BezList1 = MakeBezierCurves( fuseBack, Pt1, Pt2, Pt3, Pt4, Dir, Param, NumCols, NumRows ); Pt1 = point( 2.7, -5, -0.05 ); Pt2 = point( 4.0, -5, -0.05 ); Pt3 = point( 4.0, -5, 0.7 ); Pt4 = point( 2.7, -5, 0.7 ); Dir = vector( 0, 1, 0 ); view( list( fuseBack, Pt1, Pt2, Pt3, Pt4 ), on ); BezList2 = MakeBezierCurves( fuseBack, Pt1, Pt2, Pt3, Pt4, Dir, Param, NumCols, NumRows ); Pt1 = point( 10.0, 5, 0.1 ); Pt2 = point( 10.5, 5, 0.1 ); Pt3 = point( 10.5, 5, 0.37 ); Pt4 = point( 10.0, 5, 0.37 ); Dir = vector( 0, -1, 0 ); view( list( fuseBack, Pt1, Pt2, Pt3, Pt4 ), on ); BezList3 = MakeBezierCurves( fuseBack, Pt1, Pt2, Pt3, Pt4, Dir, Param, NumCols, NumRows ); Pt1 = point( 10.0, -5, 0.1 ); Pt2 = point( 10.5, -5, 0.1 ); Pt3 = point( 10.5, -5, 0.37 ); Pt4 = point( 10.0, -5, 0.37 ); Dir = vector( 0, 1, 0 ); view( list( fuseBack, Pt1, Pt2, Pt3, Pt4 ), on ); BezList4 = MakeBezierCurves( fuseBack, Pt1, Pt2, Pt3, Pt4, Dir, Param, NumCols, NumRows ); view( list( BezList1, BezList2, BezList3, BezList4, FuseParamSpace ), on ); All = list( list( NumCols, NumRows ), BezList1, BezList2, BezList3, BezList4, FuseParamSpace ); save( "FuseBez" + Postfix, All ); free( BezList1 ); free( BezList2 ); free( BezList3 ); free( BezList4 ); free( FuseParamSpace ); free( All ); free( fuseBack ); ############################################################################# # # The steering (vertical) tail. # c1 = ( cbspline( 3, list( ctlpt( E3, 0.0, 0.0, 0.0 ), ctlpt( E3, 0.0, 0.02, 0.0 ), ctlpt( E3, 1.5, 0.07, 0.0 ), ctlpt( E3, 3.0, 0.0, 0.0 ) ), list( KV_OPEN ) ) + cbspline( 3, list( ctlpt( E3, 3.0, 0.0, 0.0 ), ctlpt( E3, 1.5, -0.07, 0.0 ), ctlpt( E3, 0.0, -0.02, 0.0 ), ctlpt( E3, 0.0, 0.0, 0.0 ) ), list( KV_OPEN ) ) ) * trans( vector( 7.7, 0.0, 0.3 ) ); c2 = c1 * scale( vector( 0.65, 0.65, 0.65 ) ) * trans( vector( 3.75, 0.0, 0.4 ) ); c3 = c1 * scale( vector( 0.16, 0.16, 0.16 ) ) * trans( vector( 9.5, 0.0, 2.0 ) ); vTail2 = ruledsrf( c2, c3 ); color( vTail2, red ); TailParamSpace = poly( list( point( 0, 0, 0 ), point( 4, 0, 0 ), point( 4, 1, 0 ), point( 0, 1, 0 ), point( 0, 0, 0 ) ), true ); color( TailParamSpace, yellow ); Resolution = 50; Pt1 = point( 9.9, -5, 0.7 ); Pt2 = point( 10.65, -5, 0.7 ); Pt3 = point( 10.65, -5, 1.35 ); Pt4 = point( 9.9, -5, 1.35 ); Dir = vector( 0, 1, 0 ); view( list( vTail2, Pt1, Pt2, Pt3, Pt4 ), on ); BezList5 = MakeBezierCurves( vTail2, Pt1, Pt2, Pt3, Pt4, Dir, Param, NumCols, NumRows ); Pt1 = point( 9.9, 5, 0.7 ); Pt2 = point( 10.65, 5, 0.7 ); Pt3 = point( 10.65, 5, 1.35 ); Pt4 = point( 9.9, 5, 1.35 ); Dir = vector( 0, -1, 0 ); view( list( vTail2, Pt1, Pt2, Pt3, Pt4 ), on ); BezList6 = MakeBezierCurves( vtail2, Pt1, Pt2, Pt3, Pt4, Dir, Param, NumCols, NumRows ); view( list( BezList5, BezList6, tailParamSpace ), on ); All = list( list( NumCols, NumRows ), BezList5, BezList6, tailParamSpace ); save( "TailBez" + Postfix, All ); free( BezList5 ); free( BezList6 ); free( tailParamSpace ); free( All ); free( vtail2 ); ############################################################################# free( Param ); free( NumCols ); free( NumRows ); free( Postfix ); free( c1 ); free( c2 ); free( c3 ); free( c4 ); free( c5 ); free( c6 ); free( c7 ); free( Pt1 ); free( Pt2 ); free( Pt3 ); free( Pt4 ); free( Dir );