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More resistance to degnerate normals
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@pboyer
pboyer committed Nov 29, 2014
1 parent c46ac93 commit 58d7e7e
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122 changes: 85 additions & 37 deletions build/verb.js
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Original file line number Diff line number Diff line change
Expand Up @@ -1138,7 +1138,7 @@ verb.geom.NurbsCurve.prototype.point = function( u, callback ) {

verb.geom.NurbsCurve.prototype.derivatives = function( u, num_derivs, callback ) {

return this.nurbsEngine.eval( 'rational_curve_derivs', [ this.get('degree'), this.get('knots'), this.homogenize(), u, num_derivs ], callback );
return this.nurbsEngine.eval( 'rational_curve_derivs', [ this.get('degree'), this.get('knots'), this.homogenize(), u, num_derivs || 1 ], callback );

};

Expand Down Expand Up @@ -1382,7 +1382,7 @@ verb.geom.NurbsSurface.prototype.point = function( u, v, callback ) {
verb.geom.NurbsSurface.prototype.derivatives = function( u, v, num_derivs, callback ) {

return this.nurbsEngine.eval( 'rational_surface_derivs',
[ this.get('degreeU'), this.get('knotsU'), this.get('degreeV'), this.get('knotsV'), this.homogenize(), num_derivs, u, v ], callback );
[ this.get('degreeU'), this.get('knotsU'), this.get('degreeV'), this.get('knotsV'), this.homogenize(), num_derivs || 1, u, v ], callback );

};

Expand Down Expand Up @@ -4276,32 +4276,31 @@ verb.eval.nurbs.rational_curve_adaptive_sample_range = function( degree, knots,
mid_u = start_u + (end_u - start_u) * t,
p2 = verb.eval.nurbs.rational_curve_point(degree, knots, control_points, mid_u);

// if the two end control points are coincident, the three point test will always return 0, let's split the curve
var diff = numeric.sub( p1, p3);
var diff2 = numeric.sub( p1, p2);
// if the two end control points are coincident, the three point test will always return 0, let's split the curve
var diff = numeric.sub( p1, p3);
var diff2 = numeric.sub( p1, p2);

// the first condition checks if the curve makes up a loop, if so, we will need to continue evaluation
if ( ( numeric.dot( diff, diff ) < tol && numeric.dot( diff2, diff2 ) > tol ) || !verb.eval.nurbs.three_points_are_flat( p1, p2, p3, tol ) ) {
// the first condition checks if the curve makes up a loop, if so, we will need to continue evaluation
if ( ( numeric.dot( diff, diff ) < tol && numeric.dot( diff2, diff2 ) > tol ) || !verb.eval.nurbs.three_points_are_flat( p1, p2, p3, tol ) ) {

// get the exact middle
var exact_mid_u = start_u + (end_u - start_u) * 0.5;
// get the exact middle
var exact_mid_u = start_u + (end_u - start_u) * 0.5;

// recurse on the two halves
var left_pts = verb.eval.nurbs.rational_curve_adaptive_sample_range( degree, knots, control_points, start_u, exact_mid_u, tol, include_u )
, right_pts = verb.eval.nurbs.rational_curve_adaptive_sample_range( degree, knots, control_points, exact_mid_u, end_u, tol, include_u );
// recurse on the two halves
var left_pts = verb.eval.nurbs.rational_curve_adaptive_sample_range( degree, knots, control_points, start_u, exact_mid_u, tol, include_u )
, right_pts = verb.eval.nurbs.rational_curve_adaptive_sample_range( degree, knots, control_points, exact_mid_u, end_u, tol, include_u );

// concatenate the two
return left_pts.slice(0, -1).concat(right_pts);
// concatenate the two
return left_pts.slice(0, -1).concat(right_pts);

} else {

if (include_u){
return [ [ start_u ].concat(p1) , [end_u].concat(p3) ];
} else {
return [ p1, p3 ];
}
} else {

if (include_u){
return [ [ start_u ].concat(p1) , [end_u].concat(p3) ];
} else {
return [ p1, p3 ];
}
}
}

//
Expand Down Expand Up @@ -4354,6 +4353,7 @@ verb.eval.nurbs.divide_rational_surface_adaptive = function( degree_u, knots_u,
options = options || {};
options.minDivsU = options.minDivsU || 1;
options.minDivsV = options.minDivsV || 1;
options.refine = options.refine != undefined ? options.refine : true;

var divsU = options.minDivsU = Math.max( options.minDivsU, (homo_control_points.length - 1) * 3 );
var divsV = options.minDivsV = Math.max( options.minDivsV, (homo_control_points.length - 1) * 3 );
Expand Down Expand Up @@ -4388,9 +4388,12 @@ verb.eval.nurbs.divide_rational_surface_adaptive = function( degree_u, knots_u,
u,
v );

var norm = numeric.normalized( numeric.cross( ds[0][1], ds[1][0] ) );
ptrow.push( new verb.geom.SurfacePoint( ds[0][0],
numeric.normalized( numeric.cross( ds[0][1], ds[1][0] ) ),
[u,v] ) );
norm,
[u,v],
null,
verb.isZero( norm ) ) );
}
pts.push( ptrow );
}
Expand All @@ -4407,6 +4410,8 @@ verb.eval.nurbs.divide_rational_surface_adaptive = function( degree_u, knots_u,
}
}

if (!options.refine) return divs;

// 3) assign all of the neighbors and divide
for (i = 0; i < divsV; i++){
for (j = 0; j < divsU; j++){
Expand All @@ -4418,7 +4423,7 @@ verb.eval.nurbs.divide_rational_surface_adaptive = function( degree_u, knots_u,
, w = verb.west( ci, i, j, divsU, divsV, divs );

divs[ci].neighbors = [ s, e, n, w ];
divs[ci].divide( options );
divs[ci].divide( options );
}
}

Expand Down Expand Up @@ -4491,15 +4496,16 @@ verb.eval.nurbs.dist_to_seg = function(a, b, c){

}

verb.geom.SurfacePoint = function(point, normal, uv, id){
verb.geom.SurfacePoint = function(point, normal, uv, id, degen){
this.uv = uv;
this.point = point;
this.normal = normal;
this.id = id;
this.degen = degen;
}

verb.geom.SurfacePoint.fromUv = function(u,v){
return new verb.geom.SurfacePoint(null, null, [u,v], null);
return new verb.geom.SurfacePoint(null, null, [u,v], null, null);
}

verb.geom.TriMesh = function(faces, points, uvs, normals){
Expand Down Expand Up @@ -4598,14 +4604,18 @@ verb.eval.nurbs.AdaptiveRefinementNode.prototype.evalSrf = function( u, v, srfPt
u,
v );
var pt = derivs[0][0];
var norm = numeric.normalized( numeric.cross( derivs[0][1], derivs[1][0] ) );
var norm = numeric.cross( derivs[0][1], derivs[1][0] );
var degen = verb.isZero( norm );

if (!degen) norm = numeric.normalized( norm );

if (srfPt){
srfPt.degen = degen;
srfPt.point = pt;
srfPt.normal = norm;
return srfPt;
} else {
return new verb.geom.SurfacePoint( pt, norm, [u,v] );
return new verb.geom.SurfacePoint( pt, norm, [u,v], null, degen );
}

};
Expand Down Expand Up @@ -4701,26 +4711,64 @@ verb.eval.nurbs.AdaptiveRefinementNode.prototype.midpoint = function( index ){

}

verb.isZero = function( vec ){

for (var i = 0, l = vec.length; i < l; i++){
if (Math.abs( vec[i] ) > verb.TOLERANCE ) return false;
}

return true;
}

verb.eval.nurbs.AdaptiveRefinementNode.prototype.hasBadNormals = function( vec ){
return this.corners[0].degen || this.corners[1].degen || this.corners[2].degen || this.corners[3].degen;
}

verb.eval.nurbs.AdaptiveRefinementNode.prototype.fixNormals = function(){
for (var i = 0, l = this.corners.length; i < l; i++){

var corn = this.corners[i];

if (this.corners[i].degen) {

// get neighbors
var v1 = this.corners[(i + 1) % l];
var v2 = this.corners[(i + 3) % l];

// correct the normal
this.corners[i].normal = v1.degen ? v2.normal : v1.normal;

}

}
}

verb.eval.nurbs.AdaptiveRefinementNode.prototype.shouldDivide = function( options, currentDepth ){

if ( currentDepth < options.minDepth ) return true;
if ( currentDepth >= options.maxDepth ) return false;

this.divideVertical = numeric.norm2Squared( numeric.sub( this.corners[0].normal, this.corners[1].normal ) ) > options.normTol ||
if ( this.hasBadNormals() ) {
this.fixNormals();
// don't divide any further when encountering a degenerate normal
return false;
}

this.splitVert = numeric.norm2Squared( numeric.sub( this.corners[0].normal, this.corners[1].normal ) ) > options.normTol ||
numeric.norm2Squared( numeric.sub( this.corners[2].normal, this.corners[3].normal ) ) > options.normTol;

this.divideHorizontal = numeric.norm2Squared( numeric.sub( this.corners[1].normal, this.corners[2].normal ) ) > options.normTol ||
this.splitHoriz = numeric.norm2Squared( numeric.sub( this.corners[1].normal, this.corners[2].normal ) ) > options.normTol ||
numeric.norm2Squared( numeric.sub( this.corners[3].normal, this.corners[0].normal ) ) > options.normTol;

// is curved in u direction?
// this.divideVertical = verb.eval.nurbs.dist_to_seg( this.corners[0].point, this.midpoints[0].point, this.corners[1].point ) > options.edgeTol ||
// this.splitVert = verb.eval.nurbs.dist_to_seg( this.corners[0].point, this.midpoints[0].point, this.corners[1].point ) > options.edgeTol ||
// verb.eval.nurbs.dist_to_seg( this.corners[2].point, this.midpoints[2].point, this.corners[3].point ) > options.edgeTol;

// // is curved in v direction?
// this.divideHorizontal = verb.eval.nurbs.dist_to_seg( this.corners[1].point, this.midpoints[1].point, this.corners[2].point ) > options.edgeTol ||
// this.splitHoriz = verb.eval.nurbs.dist_to_seg( this.corners[1].point, this.midpoints[1].point, this.corners[2].point ) > options.edgeTol ||
// verb.eval.nurbs.dist_to_seg( this.corners[0].point, this.midpoints[3].point, this.corners[3].point ) > options.edgeTol;

if ( this.divideVertical || this.divideHorizontal ) return true;
if ( this.splitVert || this.splitHoriz ) return true;

var center = this.center();

Expand All @@ -4736,7 +4784,7 @@ verb.eval.nurbs.AdaptiveRefinementNode.prototype.divide = function( options ){
options.edgeTol = options.edgeTol || 0.1;
options.normTol = options.normTol || 5e-2;
options.minDepth = options.minDepth != undefined ? options.minDepth : 0;
options.maxDepth = options.maxDepth != undefined ? options.maxDepth : 20;
options.maxDepth = options.maxDepth != undefined ? options.maxDepth : 10;

this._divide( options, 0, true );

Expand All @@ -4751,9 +4799,9 @@ verb.eval.nurbs.AdaptiveRefinementNode.prototype._divide = function( options, cu
currentDepth++;

// is the quad flat in one dir and curved in the other?
if (this.divideVertical && !this.divideHorizontal) {
if (this.splitVert && !this.splitHoriz) {
horiz = false;
} else if (!this.divideVertical && this.divideHorizontal){
} else if (!this.splitVert && this.splitHoriz){
horiz = true;
}

Expand Down Expand Up @@ -4858,7 +4906,7 @@ verb.eval.nurbs.AdaptiveRefinementNode.prototype.triangulateLeaf = function( mes

// all done
return mesh;

} else if (uvs.length === 5){

// use the splitcorner to triangulate
Expand Down
6 changes: 3 additions & 3 deletions build/verb.min.js
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