int RebuildNormals()
{
// We assume it always happens AFTER RebuildVertices
normals.Resize(vertices.Length);
InteropLogger.Debug($"RebuildNormals name={Name}, Length={normals.Length}");
// Normals need to be cast from short -> float from Blender
var normalScale = 1f / 32767f;
for (int i = 0; i < verts.Length; i++)
{
var vert = verts[i];
// Like vertex coordinates - we swizzle y/z
normals[i] = new InteropVector3(
vert.no_x * normalScale,
vert.no_z * normalScale,
vert.no_y * normalScale
);
}
// Also update all existing split vertices to match
// the original normal that may have been updated
foreach (var kv in splitVertices)
{
var vertIndex = (int)loops[kv.Key].v;
normals[kv.Value] = normals[vertIndex];
}
// For now we have no splits. Eventually this may
// change if we add support for split normals
// coming from a CustomData layer
return(0);
}
int RebuildVertices()
{
// We resize to the number of vertices from Blender
// PLUS the number of split vertices we already calculated
// in a prior pass (thus already have the data filled out)
vertices.Resize(verts.Length + splitVertices.Count);
InteropLogger.Debug($"RebuildVertices name={Name}, Length={vertices.Length}");
for (int i = 0; i < verts.Length; i++)
{
var vert = verts[i];
// y/z are swizzled here to convert to Unity's coordinate space
vertices[i] = new InteropVector3(
vert.co_x,
vert.co_z,
vert.co_y
);
}
// Also update all existing split vertices to match
// the original vertex that may have been updated
foreach (var kv in splitVertices)
{
var vertIndex = (int)loops[kv.Key].v;
vertices[kv.Value] = vertices[vertIndex];
}
// This will never split
return(0);
}
internal bool Approx(InteropVector3 v)
{
var epsilon = 1e-6f;
return(Math.Abs(x - v.x) < epsilon &&
Math.Abs(y - v.y) < epsilon &&
Math.Abs(z - v.z) < epsilon);
}
/// <summary>
/// Copy all mesh data - aligned to loops (thus no combination of like-vertices)
/// </summary>
internal void CopyMeshDataAlignedtoLoops(
MVert[] verts,
MLoop[] loops,
MLoopTri[] loopTris,
MLoopCol[] loopCols,
List <MLoopUV[]> loopUVs
)
{
#if LEGACY
Reallocate(loops.Length, loopTris.Length, loopUVs.Count, loopCols != null);
// Normals need to be cast from short -> float from Blender
var normalScale = 1f / 32767f;
for (int i = 0; i < loops.Length; i++)
{
var co = verts[loops[i].v].co;
var no = verts[loops[i].v].no;
_vertices[i] = new InteropVector3(co[0], co[1], co[2]);
_normals[i] = new InteropVector3(
no[0] * normalScale,
no[1] * normalScale,
no[2] * normalScale
);
// Copy UV layers - same length as loops
for (int layer = 0; layer < loopUVs.Count; layer++)
{
_uvs[layer][i] = new InteropVector2(
loopUVs[layer][i].uv
);
}
// Copy vertex colors - same length as loops
if (loopCols != null)
{
var col = loopCols[i];
_colors[i] = new InteropColor32(
col.r,
col.g,
col.b,
col.a
);
}
}
// Copy triangles
for (uint t = 0; t < loopTris.Length; t++)
{
for (uint i = 0; i < 3; i++)
{
_triangles[(t * 3) + i] = loopTris[t].tri[i];
}
}
#endif
}
public static Vector3 ToVector3(this InteropVector3 vec)
{
return(new Vector3(vec.x, vec.y, vec.z));
}
/// <summary>
/// Copy all mesh data from Blender in one go and optimize down as much as possible.
/// </summary>
/// <remarks>
/// Reference: LuxCoreRender/LuxCore::Scene_DefineBlenderMesh
/// for the logic dealing with split normals / UVs / etc.
/// </remarks>
/// <param name="verts"></param>
/// <param name="loops"></param>
/// <param name="loopTris"></param>
/// <param name="loopUVs"></param>
/// <param name="loopCols"></param>
internal void CopyMeshData_V1(
MVert[] verts,
MLoop[] loops,
MLoopTri[] loopTris,
MLoopCol[] loopCols,
List <MLoopUV[]> loopUVs
)
{
#if LEGACY
// In the case of split vertices - this'll resize DOWN
// and then resize UP again for split vertices.
Reallocate(verts.Length, loopTris.Length, loopUVs.Count, loopCols != null);
var normalScale = 1f / 32767f;
// Copy in vertex coordinates and normals
for (int i = 0; i < verts.Length; i++)
{
var co = verts[i].co;
var no = verts[i].no;
_vertices[i] = new InteropVector3(co[0], co[1], co[2]);
// Normals need to be cast from short -> float from Blender
_normals[i] = new InteropVector3(
no[0] * normalScale,
no[1] * normalScale,
no[2] * normalScale
);
}
// Copy UV layers
for (int layer = 0; layer < loopUVs.Count; layer++)
{
var uvLayer = _uvs[layer];
for (uint i = 0; i < loopUVs[layer].Length; i++)
{
var vertIndex = loops[i].v;
// This will overwrite itself for shared vertices - that's fine.
// We'll be handling split UVs when reading in triangle data.
uvLayer[vertIndex] = new InteropVector2(
loopUVs[layer][i].uv
);
}
}
// Copy vertex colors if we got 'em
if (loopCols != null)
{
for (uint i = 0; i < loopCols.Length; i++)
{
var vertIndex = loops[i].v;
var col = loopCols[i];
_colors[vertIndex] = new InteropColor32(
col.r,
col.g,
col.b,
col.a
);
}
}
// Track what triangle vertices need to be split.
// This maps an index in `triangles` to an index in `loops`
var splitTris = new Dictionary <uint, uint>();
// Generate triangle list while identifying any vertices that will need
// to be split - due to having split UVs, normals, etc in the loop data.
for (uint t = 0; t < loopTris.Length; t++)
{
for (uint i = 0; i < 3; i++)
{
var loopIndex = loopTris[t].tri[i];
var vertIndex = loops[loopIndex].v;
var split = false; // Assumes .v is already < verts.Length
// TODO: Test differing normals - not applicable
// here as normals are only read in from MVert
// Determine if we should make a new vertex for split UVs
for (int layer = 0; layer < loopUVs.Count && !split; layer++)
{
var loopUV = loopUVs[layer][loopIndex].uv;
var vertUV = _uvs[layer][vertIndex];
// TODO: Handle floating point errors?
if (loopUV[0] != vertUV.x || loopUV[1] != vertUV.y)
{
split = true;
}
}
// If we have vertex colors, check for split colors
if (loopCols != null)
{
var col = loopCols[loopIndex];
var vertCol = _colors[vertIndex];
if (col.r != vertCol.r ||
col.g != vertCol.g ||
col.b != vertCol.b ||
col.a != vertCol.a
)
{
split = true;
}
}
_triangles[(t * 3) + i] = vertIndex;
// Track if we need to split the vertex in the triangle
// to a new one once we've iterated through everything
if (split)
{
splitTris.Add((t * 3) + i, loopIndex);
}
}
}
// 7958 + 32245 = 40203
// LOOPS are 31488
// 7958 * 3 = 23874
// 15744 loop triangles
// 31488 vertex color indices
// If we have triangle verts to split - apply all at once so there's
// only a single re-allocation to our arrays.
var totalNewVertices = splitTris.Count;
if (totalNewVertices > 0)
{
InteropLogger.Debug($"Splitting {totalNewVertices} vertices");
var newVertIndex = (uint)verts.Length;
// Reallocate everything to fit the new set of vertices
Reallocate(verts.Length + totalNewVertices, loopTris.Length, loopUVs.Count, loopCols != null);
// Generate new vertices with any split data (normals, UVs, colors, etc)
foreach (var tri in splitTris.Keys)
{
var prevVertIndex = _triangles[tri]; // MVert index
var loopIndex = splitTris[tri]; // MLoop index
// Same coordinates as the original vertex
_vertices[newVertIndex] = _vertices[prevVertIndex];
// TODO: If there were split normals, that'd be handled here.
_normals[newVertIndex] = _normals[prevVertIndex];
// Read UVs from loops again to handle any split UVs
for (int layer = 0; layer < loopUVs.Count; layer++)
{
var uv = loopUVs[layer][loopIndex].uv;
_uvs[layer][newVertIndex] = new InteropVector2(uv);
}
// Same deal for vertex colors - copy from the loop
if (loopCols != null)
{
var col = loopCols[loopIndex];
_colors[newVertIndex] = new InteropColor32(
col.r,
col.g,
col.b,
col.a
);
}
// And finally update the triangle to point to the new vertex
_triangles[tri] = newVertIndex;
newVertIndex++;
}
}
#endif
}
/// <summary>
/// Copy an <see cref="MVert"/> array into <see cref="Vertices"/> and <see cref="Normals"/>.
/// </summary>
/// <param name="verts"></param>
internal void CopyFromMVerts(MVert[] verts)
{
var count = verts.Length;
if (vertices == null)
{
vertices = new InteropVector3[count];
}
if (normals == null)
{
normals = new InteropVector3[count];
}
Array.Resize(ref vertices, count);
Array.Resize(ref normals, count);
// We're copying the data instead of sending directly into shared memory
// because we cannot guarantee that:
// 1. shared memory will be available for write when this is called
// 2. the source MVert array hasn't been reallocated once shared
// memory *is* available for write
// TODO: "Smart" dirtying.
// If verts don't change, don't flag for updates.
// Or if verts change, only update a region of the verts.
// Could do a BeginChangeCheck() ... EndChangeCheck() with
// a bool retval if changes happened.
// The idea is to do as much work as possible locally within
// Blender to transmit the smallest deltas to Unity.
// On a resize - this is just everything.
int rangeStart = count;
int rangeEnd = 0;
int changedVertexCount = 0;
for (int i = 0; i < count; i++)
{
var co = verts[i].co;
var no = verts[i].no;
var newVert = new InteropVector3(co[0], co[1], co[2]);
// Normals need to be cast from short -> float
var newNorm = new InteropVector3(no[0] / 32767f, no[1] / 32767f, no[2] / 32767f);
if (!newVert.Approx(vertices[i]) || !newNorm.Approx(normals[i]))
{
rangeStart = Math.Min(rangeStart, i);
rangeEnd = Math.Max(rangeEnd, i);
changedVertexCount++;
}
vertices[i] = newVert;
normals[i] = newNorm;
// TECHNICALLY I can collect an index list of what changed and send just
// that to Unity - but is it really worth the extra effort? We'll see!
// Console.WriteLine($" - v={vertices[i]}, n={normals[i]}");
// Other issue is that changes may affect index 0, 1, and 1000, 1001 for a quad.
// Or a change has shifted vertices around in the array due to some sort of
// esoteric Blender operator. So to play it safe, we just update the whole array
// until it can be guaranteed that we can identify an accurate slice of updates.
}
InteropLogger.Debug(
$"** Changed {changedVertexCount} vertices within index range " +
$"[{rangeStart}, {rangeEnd}] covering {rangeEnd - rangeStart} vertices"
);
}