I've already posted this in the bugs database, but thought I'd also post it here so people can see it.

It looks lik beginRaw() incorrectly exports the result of the last beginShape()/endShape() command twice, resulting in duplicate 3D faces that can cause problems for some 3D software. The code below should produce 12 3D faces (3 sets of 2 quads == 12 triangles), but in fact produces 16 because the last two quads are exported twice.

A possible workaround would be to explicitly instantiate a processing.dxf.RawDXF or similar exporter class and make beginShape() and vertex() calls directly.

Code:

void setup() {
size(400,400,P3D);
noLoop();
}

void draw() {
beginRaw(DXF,"test.dxf");

noStroke();
for(int i=0; i<3; i++) {
beginShape(QUAD_STRIP);
vertex(0,i*100,0);
vertex(0,(i+1)*100,0);
vertex(100,i*100,0);
vertex(100,(i+1)*100,0);
vertex(200,i*100,0);
vertex(200,(i+1)*100,0);
endShape();
}

endRaw();
}