From 95e31c9f028d4dde530ef28c5b80d62df0f93e6b Mon Sep 17 00:00:00 2001 From: Teravus Ovares Date: Tue, 8 Apr 2008 05:03:43 +0000 Subject: * Added stretchable ellipsoid support with configurable LOD. It's actually a split facet icosahedral geodesic sphere that's scaled. * In other words, you can stretch spheres into oblong shapes now and watch them roll around like a football would. * Still can't cut, twist or profile cut spheres yet. --- OpenSim/Region/Physics/Meshing/HelperTypes.cs | 77 +++++++++++++ OpenSim/Region/Physics/Meshing/Meshmerizer.cs | 151 ++++++++++++++++---------- 2 files changed, 168 insertions(+), 60 deletions(-) (limited to 'OpenSim') diff --git a/OpenSim/Region/Physics/Meshing/HelperTypes.cs b/OpenSim/Region/Physics/Meshing/HelperTypes.cs index 6c4a163..7b17a3f 100644 --- a/OpenSim/Region/Physics/Meshing/HelperTypes.cs +++ b/OpenSim/Region/Physics/Meshing/HelperTypes.cs @@ -39,6 +39,83 @@ public class Vertex : PhysicsVector, IComparable { } + public float length() + { + return (float)Math.Sqrt(X * X + Y * Y + Z * Z); + } + + public Vertex normalize() + { + float tlength = length(); + if (tlength != 0) + { + return new Vertex(X / tlength, Y / tlength, Z / tlength); + } + else + { + return new Vertex(0, 0, 0); + } + } + + public Vertex cross(Vertex v) + { + return new Vertex(Y * v.Z - Z * v.Y, Z * v.X - X * v.Z, X * v.Y - Y * v.X); + } + + public static Vertex operator +(Vertex v1, Vertex v2) + { + return new Vertex(v1.X + v2.X, v1.Y + v2.Y, v1.Z + v2.Z); + } + + public static Vertex operator -(Vertex v1, Vertex v2) + { + return new Vertex(v1.X - v2.X, v1.Y - v2.Y, v1.Z - v2.Z); + } + + public static Vertex operator *(Vertex v1, Vertex v2) + { + return new Vertex(v1.X * v2.X, v1.Y * v2.Y, v1.Z * v2.Z); + } + + public static Vertex operator +(Vertex v1, float am) + { + v1.X += am; + v1.Y += am; + v1.Z += am; + return v1; + } + public static Vertex operator -(Vertex v1, float am) + { + v1.X -= am; + v1.Y -= am; + v1.Z -= am; + return v1; + } + public static Vertex operator *(Vertex v1, float am) + { + v1.X *= am; + v1.Y *= am; + v1.Z *= am; + return v1; + } + public static Vertex operator /(Vertex v1, float am) + { + if (am == 0f) + { + return new Vertex(0f,0f,0f); + } + v1.X /= am; + v1.Y /= am; + v1.Z /= am; + return v1; + } + + + public float dot(Vertex v) + { + return X * v.X + Y * v.Y + Z * v.Z; + } + public Vertex(PhysicsVector v) : base(v.X, v.Y, v.Z) { diff --git a/OpenSim/Region/Physics/Meshing/Meshmerizer.cs b/OpenSim/Region/Physics/Meshing/Meshmerizer.cs index d668aa3..80f5bd1 100644 --- a/OpenSim/Region/Physics/Meshing/Meshmerizer.cs +++ b/OpenSim/Region/Physics/Meshing/Meshmerizer.cs @@ -989,8 +989,17 @@ namespace OpenSim.Region.Physics.Meshing return result; } private static Mesh CreateSphereMesh(String primName, PrimitiveBaseShape primShape, PhysicsVector size) - // Builds the z (+ and -) surfaces of a box shaped prim { + // Builds an icosahedral geodesic sphere + // based on an article by Paul Bourke + // http://local.wasp.uwa.edu.au/~pbourke/ + // articles: + // http://local.wasp.uwa.edu.au/~pbourke/geometry/polygonmesh/ + // and + // http://local.wasp.uwa.edu.au/~pbourke/geometry/polyhedra/index.html + + // Still have more to do here. + UInt16 hollowFactor = primShape.ProfileHollow; UInt16 profileBegin = primShape.ProfileBegin; UInt16 profileEnd = primShape.ProfileEnd; @@ -999,13 +1008,17 @@ namespace OpenSim.Region.Physics.Meshing UInt16 pathShearX = primShape.PathShearX; UInt16 pathShearY = primShape.PathShearY; Mesh m = new Mesh(); - float radius = 0.6f; + + float LOD = 0.2f; + float diameter = 0.5f;// Our object will result in -0.5 to 0.5 float sq5 = (float) Math.Sqrt(5.0); float phi = (1 + sq5) * 0.5f; float rat = (float) Math.Sqrt(10f + (2f * sq5)) / (4f * phi); - float a = (radius / rat) * 0.5f; - float b = (radius / rat) / (2.0f * phi); + float a = (diameter / rat) * 0.5f; + float b = (diameter / rat) / (2.0f * phi); + + // 12 Icosahedron vertexes Vertex v1 = new Vertex(0f, b, -a); Vertex v2 = new Vertex(b, a, 0f); Vertex v3 = new Vertex(-b, a, 0f); @@ -1018,72 +1031,47 @@ namespace OpenSim.Region.Physics.Meshing Vertex v10 = new Vertex(-a, 0f, -b); Vertex v11 = new Vertex(b, -a, 0); Vertex v12 = new Vertex(-b, -a, 0); - m.Add(v1); - m.Add(v2); - m.Add(v3); - m.Add(v4); - m.Add(v5); - m.Add(v6); - m.Add(v7); - m.Add(v8); - m.Add(v9); - m.Add(v10); - m.Add(v11); - m.Add(v12); - - Triangle t1 = new Triangle(v1, v2, v3); - Triangle t2 = new Triangle(v4, v3, v2); - Triangle t3 = new Triangle(v4, v5, v6); - Triangle t4 = new Triangle(v4, v9, v5); - Triangle t5 = new Triangle(v1, v7, v8); - Triangle t6 = new Triangle(v1, v10, v7); - Triangle t7 = new Triangle(v5, v11, v12); - Triangle t8 = new Triangle(v7, v12, v11); - Triangle t9 = new Triangle(v3, v6, v10); - Triangle t10 = new Triangle(v12, v10, v6); - Triangle t11 = new Triangle(v2, v8, v9); - Triangle t12 = new Triangle(v11, v9, v8); - Triangle t13 = new Triangle(v4, v6, v3); - Triangle t14 = new Triangle(v4, v2, v9); - Triangle t15 = new Triangle(v1, v3, v10); - Triangle t16 = new Triangle(v1, v8, v2); - Triangle t17 = new Triangle(v7, v10, v12); - Triangle t18 = new Triangle(v7, v11, v8); - Triangle t19 = new Triangle(v5, v12, v6); - Triangle t20 = new Triangle(v5, v9, v11); - m.Add(t1); - m.Add(t2); - m.Add(t3); - m.Add(t4); - m.Add(t5); - m.Add(t6); - m.Add(t7); - m.Add(t8); - m.Add(t9); - m.Add(t10); - m.Add(t11); - m.Add(t12); - m.Add(t13); - m.Add(t14); - m.Add(t15); - m.Add(t16); - m.Add(t17); - m.Add(t18); - m.Add(t19); - m.Add(t20); - - // strechy! + + + + // Base Faces of the Icosahedron (20) + SphereLODTriangle(v1, v2, v3, diameter, LOD, m); + SphereLODTriangle(v4, v3, v2, diameter, LOD, m); + SphereLODTriangle(v4, v5, v6, diameter, LOD, m); + SphereLODTriangle(v4, v9, v5, diameter, LOD, m); + SphereLODTriangle(v1, v7, v8, diameter, LOD, m); + SphereLODTriangle(v1, v10, v7, diameter, LOD, m); + SphereLODTriangle(v5, v11, v12, diameter, LOD, m); + SphereLODTriangle(v7, v12, v11, diameter, LOD, m); + SphereLODTriangle(v3, v6, v10, diameter, LOD, m); + SphereLODTriangle(v12, v10, v6, diameter, LOD, m); + SphereLODTriangle(v2, v8, v9, diameter, LOD, m); + SphereLODTriangle(v11, v9, v8, diameter, LOD, m); + SphereLODTriangle(v4, v6, v3, diameter, LOD, m); + SphereLODTriangle(v4, v2, v9, diameter, LOD, m); + SphereLODTriangle(v1, v3, v10, diameter, LOD, m); + SphereLODTriangle(v1, v8, v2, diameter, LOD, m); + SphereLODTriangle(v7, v10, v12, diameter, LOD, m); + SphereLODTriangle(v7, v11, v8, diameter, LOD, m); + SphereLODTriangle(v5, v12, v6, diameter, LOD, m); + SphereLODTriangle(v5, v9, v11, diameter, LOD, m); + + // Scale the mesh based on our prim scale foreach (Vertex v in m.vertices) { v.X *= size.X; v.Y *= size.Y; v.Z *= size.Z; } + + // This was built with the normals pointing inside.. + // therefore we have to invert the normals foreach (Triangle t in m.triangles) { t.invertNormal(); } - m.DumpRaw(baseDir, primName, "Z extruded"); + // Dump the faces for visualization in blender. + m.DumpRaw(baseDir, primName, "Icosahedron"); return m; } @@ -1149,6 +1137,49 @@ namespace OpenSim.Region.Physics.Meshing } } + public static Vertex midUnitRadialPoint(Vertex a, Vertex b, float radius) + { + Vertex midpoint = new Vertex(a + b) * 0.5f; + return (midpoint.normalize() * radius); + } + + public static void SphereLODTriangle(Vertex a, Vertex b, Vertex c, float diameter, float LOD, Mesh m) + { + Vertex aa = a - b; + Vertex ba = b - c; + Vertex da = c - a; + + if (((aa.length() < LOD) && (ba.length() < LOD) && (da.length() < LOD))) + { + // We don't want duplicate verticies. Duplicates cause the scale algorithm to produce a spikeball + // spikes are novel, but we want ellipsoids. + + if (!m.vertices.Contains(a)) + m.Add(a); + if (!m.vertices.Contains(b)) + m.Add(b); + if (!m.vertices.Contains(c)) + m.Add(c); + + // Add the triangle to the mesh + Triangle t = new Triangle(a, b, c); + m.Add(t); + } + else + { + Vertex ab = midUnitRadialPoint(a, b, diameter); + Vertex bc = midUnitRadialPoint(b, c, diameter); + Vertex ca = midUnitRadialPoint(c, a, diameter); + + // Recursive! Splits the triangle up into 4 smaller triangles + SphereLODTriangle(a, ab, ca, diameter, LOD, m); + SphereLODTriangle(ab, b, bc, diameter, LOD, m); + SphereLODTriangle(ca, bc, c, diameter, LOD, m); + SphereLODTriangle(ab, bc, ca, diameter, LOD, m); + + } + } + public IMesh CreateMesh(String primName, PrimitiveBaseShape primShape, PhysicsVector size) { Mesh mesh = null; -- cgit v1.1