fix taper bug in screw GPU implementation that caused far-out visuals

soypat · Aug 17, 2024 · 7d27200 · 7d27200
1 parent 42a82f0
commit 7d27200
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Showing 3 changed files with 6 additions and 3 deletions.
diff --git a/examples/npt-flange/flange.go b/examples/npt-flange/flange.go
@@ -92,8 +92,9 @@ func scene() (gleval.SDF3, error) {
 
 	pipe, _ := threads.Nut(threads.NutParms{
 		Thread: npt,
-		Style:  threads.NutKnurl,
+		Style:  threads.NutHex,
 	})
+	pipe = gsdf.Scale(pipe, 100)
 	return makeSDF(pipe)
 	// Base plate which goes bolted to joint.
 	flange, _ = gsdf.NewCylinder(flangeD/2, flangeH, flangeH/8)

diff --git a/forge/threads/nut.go b/forge/threads/nut.go
@@ -71,7 +71,7 @@ func Nut(k NutParms) (s glbuild.Shader3D, err error) {
 		return nil, err
 	}
 	// internal thread
-	thread, err := Screw(nh, k.Thread)
+	thread, err := Screw(nh*(1+1e-2), k.Thread)
 	if err != nil {
 		return nil, err
 	}

diff --git a/forge/threads/threads.go b/forge/threads/threads.go
@@ -117,7 +117,9 @@ func (s *screw) AppendShaderBody(b []byte) []byte {
 	b = append(b, `
 #define Pi 3.1415926535897932384626433832795
 float y = length(p.xy);
-if (taper != 0.) { y += p.z * atan(p.x, taper); }
+if (taper != 0.) {
+	y += p.z * atan(taper); 
+}
 float theta = atan(p.y, p.x);
 float z = p.z + lead*theta/(2.*Pi);
 float sawt = (z + pitch/2.)/pitch;