/// <summary>
/// Updates the cached edge lengths
/// </summary>
public void updateInfo()
{
float best = 999999999;
for (int i = 0; i < 3; i++)
{
SimplificationVertex a = verts[i];
SimplificationVertex b = verts[(i + 1) % verts.Length];
float dx = a.pos[0] - b.pos[0];
float dy = a.pos[1] - b.pos[1];
float dz = a.pos[2] - b.pos[2];
edgeLengths[i] = (dx * dx) + (dy * dy) + (dz * dz);
if (edgeLengths[i] < best)
{
best = edgeLengths[i];
minEdge = i;
}
}
}
/// <summary>
/// Simplifies the mesh provided, then places it back into the parameters.
/// </summary>
/// <remarks>
/// Repeatedly remove the shortest edge in the mesh, reducing the triangle count by two each step. This is repeated
/// until the triangle count is low enough or more than 2000 tries have been made.
/// </remarks>
/// <param name="verts">The original and final verticies. (3 elements per vertex)</param>
/// <param name="vertCount">The original and final vertex counts.</param>
/// <param name="inds">The original and final index buffer. (3 element per triangle, zero based)</param>
/// <param name="trisCount">The original and final triangle counts.</param>
private static void Simplify(ref float[] verts, ref uint vertCount, ref uint[] inds, ref uint trisCount)
{
// Setup edge relations, compute min edge lengths...
List <SimplificationVertex> simplVerts = new List <SimplificationVertex>();
for (int i = 0; i < vertCount; i++)
{
simplVerts.Add(new SimplificationVertex(verts[i * 3], verts[i * 3 + 1], verts[i * 3 + 2]));
}
List <SimplificationFace> simplFace = new List <SimplificationFace>();
for (int i = 0; i < trisCount * 3; i += 3)
{
SimplificationFace face = new SimplificationFace();
face.verts[0] = simplVerts[(int)inds[i]];
face.verts[1] = simplVerts[(int)inds[i + 1]];
face.verts[2] = simplVerts[(int)inds[i + 2]];
foreach (SimplificationVertex v in face.verts)
{
v.faces.Add(face); // Make sure all verticies know their neighbors
}
simplFace.Add(face);
}
foreach (SimplificationFace face in simplFace)
{
face.updateInfo();
}
simplFace.Sort();
#region FANCY_SIMPLIFY_GRAPHICS
#if FANCY_SIMPLIFY_GRAPHICS
double[] major, minor;
GraphicsCoordinateSet majorCoordSet, minorCoordSet;
major = new double[9 * simplFace.Count];
for (int a = 0; a < simplFace.Count; a++)
{
int off = a * 9;
simplFace[a].tmpHead = off;
Array.Copy(simplFace[a].verts[0].pos, 0, major, off, 3);
Array.Copy(simplFace[a].verts[1].pos, 0, major, off + 3, 3);
Array.Copy(simplFace[a].verts[2].pos, 0, major, off + 6, 3);
}
minor = new double[9];
AssemblyDocument part = ((AssemblyDocument)Exporter.INVENTOR_APPLICATION.ActiveDocument);
GraphicsDataSets dataSets;
try
{
dataSets = part.GraphicsDataSetsCollection.AddNonTransacting("convexHULL");
}
catch
{
dataSets = part.GraphicsDataSetsCollection["convexHULL"];
dataSets.Delete();
dataSets = part.GraphicsDataSetsCollection.AddNonTransacting("convexHULL");
}
ClientGraphics graphics;
try
{
graphics = part.ComponentDefinition.ClientGraphicsCollection.AddNonTransacting("convexHULL");
}
catch
{
graphics = part.ComponentDefinition.ClientGraphicsCollection["convexHULL"];
graphics.Delete();
graphics = part.ComponentDefinition.ClientGraphicsCollection.AddNonTransacting("convexHULL");
}
{
GraphicsNode node = graphics.AddNode(graphics.Count + 1);
majorCoordSet =
dataSets.CreateCoordinateSet(dataSets.Count + 1);
majorCoordSet.PutCoordinates(major);
LineGraphics primitive = node.AddLineGraphics();
primitive.BurnThrough = false;
//Create Coordinate Index Set
GraphicsIndexSet indexSetCoords =
dataSets.CreateIndexSet(dataSets.Count + 1);
for (int i = 0; i < major.Length; i += 3)
{
indexSetCoords.Add(indexSetCoords.Count + 1, i + 1); //from point 1
indexSetCoords.Add(indexSetCoords.Count + 1, i + 2); //connect to point 2
indexSetCoords.Add(indexSetCoords.Count + 1, i + 2); //from point 2
indexSetCoords.Add(indexSetCoords.Count + 1, i + 3); //connect to point 3
indexSetCoords.Add(indexSetCoords.Count + 1, i + 3); //from point 3
indexSetCoords.Add(indexSetCoords.Count + 1, i + 1); //connect to point 1
}
primitive.CoordinateSet = majorCoordSet;
primitive.CoordinateIndexSet = indexSetCoords;
}
{
GraphicsNode node = graphics.AddNode(graphics.Count + 1);
minorCoordSet =
dataSets.CreateCoordinateSet(dataSets.Count + 1);
minorCoordSet.PutCoordinates(minor);
TriangleGraphics primitive = node.AddTriangleGraphics();
primitive.DepthPriority = 19999;
//Create Coordinate Index Set
GraphicsColorSet colorSet = dataSets.CreateColorSet(dataSets.Count + 1);
for (int i = 0; i < minor.Length; i += 3)
{
colorSet.Add(colorSet.Count + 1, 255, 0, 0);
}
primitive.CoordinateSet = minorCoordSet;
primitive.ColorSet = colorSet;
primitive.ColorBinding = ColorBindingEnum.kPerItemColors;
//primitive.CoordinateIndexSet = indexSetCoords;
}
Exporter.INVENTOR_APPLICATION.ActiveView.Update();
#endif
#endregion
// Time for shenanigans! We are going to naively pick the shortest edge and then remove it. Destroys two faces per loop typically.
// Give it 2000 tries at most.
for (int i = 0; i < 2000 && simplFace.Count > CONVEX_HULL_FACET_LIMIT; i++)
{
SimplificationFace bFace = simplFace[0];
// This is the edge to remove
SimplificationVertex[] remove = new SimplificationVertex[] {
bFace.verts[bFace.minEdge], bFace.verts[(bFace.minEdge + 1) % bFace.verts.Length]
};
#region FANCY_SIMPLIFY_GRAPHICS
#if FANCY_SIMPLIFY_GRAPHICS
// Highlight
Array.Copy(bFace.verts[0].pos, 0, minor, 0, 3);
Array.Copy(bFace.verts[1].pos, 0, minor, 3, 3);
Array.Copy(bFace.verts[2].pos, 0, minor, 6, 3);
minorCoordSet.PutCoordinates(minor);
Exporter.INVENTOR_APPLICATION.ActiveView.Update();
#endif
#endregion
// Find the center point of the edge. One edge -> one vertex
float[] center = new float[3];
foreach (SimplificationVertex vert in remove)
{
center[0] += vert.pos[0] / 2.0f;
center[1] += vert.pos[1] / 2.0f;
center[2] += vert.pos[2] / 2.0f;
vert.faces.Clear(); // Really, never use vertex again.
}
SimplificationVertex newVertex = new SimplificationVertex(center[0], center[1], center[2]);
// Ineffeciently check each face to see if it shares a vertex with the edge
for (int k = simplFace.Count - 1; k >= 0; k--)
{
int matched = 0;
SimplificationFace face = simplFace[k];
for (int j = 0; j < face.verts.Length; j++)
{
if (face.verts[j] == remove[0] ||
face.verts[j] == remove[1])
{
face.verts[j] = newVertex;
#region FANCY_SIMPLIFY_GRAPHICS
#if FANCY_SIMPLIFY_GRAPHICS
Array.Copy(face.verts[j].pos, 0, major, face.tmpHead + (3 * j), 3);
int index = (face.tmpHead / 3) + j + 1;
majorCoordSet.Remove(index);
majorCoordSet.Add(index, Exporter.INVENTOR_APPLICATION.TransientGeometry.CreatePoint(face.verts[j].pos[0], face.verts[j].pos[1], face.verts[j].pos[2]));
#endif
#endregion
if (matched == 0)
{
newVertex.faces.Add(face);
}
matched++;
}
}
// If we share at least two verts with the edge we are dead, since the triangle ends up with two
// of the same vertex
if (matched >= 2)
{
// Degenerate
simplFace.RemoveAt(k);
foreach (SimplificationVertex v in face.verts)
{
v.faces.Remove(face);
}
}
else if (matched == 1)
{
// We changed, so update edge lengths
face.updateInfo();
}
}
simplVerts.Add(newVertex);
// Resort by edge length
simplFace.Sort();
}
simplVerts.RemoveAll((vert) => vert.faces.Count <= 0);
// Rebuild arrays
vertCount = (uint)simplVerts.Count;
verts = new float[vertCount * 3];
for (int i = 0; i < simplVerts.Count; i++)
{
int off = i * 3;
simplVerts[i].finalIndex = (i); // Our indices are zero based <3
Array.Copy(simplVerts[i].pos, 0, verts, off, 3);
}
trisCount = (uint)simplFace.Count;
inds = new uint[trisCount * 3];
for (int i = 0; i < simplFace.Count; i++)
{
int off = i * 3;
inds[off] = (uint)simplFace[i].verts[0].finalIndex;
inds[off + 1] = (uint)simplFace[i].verts[1].finalIndex;
inds[off + 2] = (uint)simplFace[i].verts[2].finalIndex;
}
}
