More comments to clarify #495

2 files changed, 6 insertions, 0 deletions

diff --git a/testdata/scad/bugs/issue495.scad b/testdata/scad/bugs/issue495.scad
index 3343113..981bedf 100644
--- a/testdata/scad/bugs/issue495.scad
+++ b/testdata/scad/bugs/issue495.scad
@@ -1,4 +1,8 @@
 // The inner cube won't render correctly in OpenCSG mode as long as this bug is present
+// Note: This causes a different bug in unstable:
+// If we render a preview first, the render() node will be cached as a PolySet. This will
+// cause the same problems as in issue495.scad. If we clear cache and render using CGAL,
+// it doesn't trigger the bug since we stay in CGAL all the time
 difference() {
   render(convexity=2) difference() {
        cube(20, center = true);
diff --git a/testdata/scad/bugs/issue495b.scad b/testdata/scad/bugs/issue495b.scad
index fb868ba..803048b 100644
--- a/testdata/scad/bugs/issue495b.scad
+++ b/testdata/scad/bugs/issue495b.scad
@@ -1,4 +1,6 @@
 // In CGAL mode, there should be a cavity
+// The problem appears to be that we don't create a correct Nef Polyhedron from
+// the polyset, probably already being wrong when converting to a Polyhedron
 difference() {
   polyhedron(convexity=2, faces=[[2,1,0],[3,1,2],[4,0,1],[4,1,5],[4,2,0],[6,2,4],[6,3,2],[7,3,6],[5,1,3],[5,3,7],[6,4,5],[6,5,7],[9,10,8],[9,11,10],[8,12,9],[9,12,13],[10,12,8],[10,14,12],[11,14,10],[11,15,14],[9,13,11],[11,13,15],[12,14,13],[13,14,15]],
 points=[[-5,-5,-5],[-5,-5,5],[-5,5,-5],[-5,5,5],[5,-5,-5],[5,-5,5],[5,5,-5],[5,5,5],[-2.5,-2.5,-2.5],[-2.5,-2.5,2.5],[-2.5,2.5,-2.5],[-2.5,2.5,2.5],[2.5,-2.5,-2.5],[2.5,-2.5,2.5],[2.5,2.5,-2.5],[2.5,2.5,2.5]]);