/// Returns true if any part of the two bounding boxes overlap.
public bool Overlaps(BBox b2)
{
var x = Max.X >= b2.Min.X && Min.X <= b2.Max.X;
var y = Max.Y >= b2.Min.Y && Min.Y <= b2.Max.Y;
var z = Max.Z >= b2.Min.Z && Min.Z <= b2.Max.Z;
return x && y && z;
}
public Scene(Primitive aggregate, IEnumerable<Light> lights, VolumeRegion volumeRegion)
{
_aggregate = aggregate;
_lights = lights;
_volumeRegion = volumeRegion;
_worldBound = aggregate.WorldBound;
if (volumeRegion != null)
_worldBound = BBox.Union(_worldBound, volumeRegion.WorldBound);
}
public BBox TransformBBox(BBox b)
{
var ret = BBox.FromPoint(TransformPoint(new Point(b.Min.X, b.Min.Y, b.Min.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Max.X, b.Min.Y, b.Min.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Min.X, b.Max.Y, b.Min.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Min.X, b.Min.Y, b.Max.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Min.X, b.Max.Y, b.Max.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Max.X, b.Max.Y, b.Min.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Max.X, b.Min.Y, b.Max.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Max.X, b.Max.Y, b.Max.Z)));
return(ret);
}
public BBox MotionBounds(BBox b, bool useInverse)
{
if (!_actuallyAnimated)
{
return(Transform.Invert(_startTransform).TransformBBox(b));
}
BBox ret = BBox.Empty;
const int nSteps = 128;
for (int i = 0; i < nSteps; ++i)
{
Transform t;
float time = MathUtility.Lerp(i / (float)(nSteps - 1), _startTime, _endTime);
Interpolate(time, out t);
if (useInverse)
{
t = Transform.Invert(t);
}
ret = BBox.Union(ret, t.TransformBBox(b));
}
return(ret);
}
public BBox MotionBounds(BBox b, bool useInverse)
{
if (!_actuallyAnimated)
return Transform.Invert(_startTransform).TransformBBox(b);
BBox ret = BBox.Empty;
const int nSteps = 128;
for (int i = 0; i < nSteps; ++i)
{
Transform t;
float time = MathUtility.Lerp(i / (float) (nSteps - 1), _startTime, _endTime);
Interpolate(time, out t);
if (useInverse)
t = Transform.Invert(t);
ret = BBox.Union(ret, t.TransformBBox(b));
}
return ret;
}
public GridAccelerator(IEnumerable<Primitive> primitives, bool refineImmediately)
{
// Initialize _primitives_ with primitives for grid
_primitives = refineImmediately
? primitives.SelectMany(prim => prim.FullyRefine()).ToArray()
: primitives.ToArray();
// Compute bounds and choose grid resolution
_bounds = BBox.Empty;
for (var i = 0; i < _primitives.Length; ++i)
_bounds = BBox.Union(_bounds, _primitives[i].WorldBound);
Vector delta = _bounds.Max - _bounds.Min;
// Find _voxelsPerUnitDist_ for grid
int maxAxis = _bounds.MaximumExtent();
float invMaxWidth = 1.0f / delta[maxAxis];
Debug.Assert(invMaxWidth > 0.0f);
float cubeRoot = 3.0f * MathUtility.Pow(_primitives.Length, 1.0f / 3.0f);
float voxelsPerUnitDist = cubeRoot * invMaxWidth;
_numVoxels = new int[3];
for (int axis = 0; axis < 3; ++axis)
{
_numVoxels[axis] = MathUtility.Round(delta[axis] * voxelsPerUnitDist);
_numVoxels[axis] = MathUtility.Clamp(_numVoxels[axis], 1, 64);
}
// Compute voxel widths and allocate voxels
for (int axis = 0; axis < 3; ++axis)
{
_width[axis] = delta[axis] / _numVoxels[axis];
_inverseWidth[axis] = (_width[axis] == 0.0f) ? 0.0f : 1.0f / _width[axis];
}
int nv = _numVoxels[0] * _numVoxels[1] * _numVoxels[2];
_voxels = new GridVoxel[nv];
// Add primitives to grid voxels
for (var i = 0; i < _primitives.Length; ++i)
{
// Find voxel extent of primitive
BBox pb = _primitives[i].WorldBound;
int[] vmin = new int[3], vmax = new int[3];
for (int axis = 0; axis < 3; ++axis)
{
vmin[axis] = PosToVoxel(ref pb.Min, axis);
vmax[axis] = PosToVoxel(ref pb.Max, axis);
}
// Add primitive to overlapping voxels
for (int z = vmin[2]; z <= vmax[2]; ++z)
for (int y = vmin[1]; y <= vmax[1]; ++y)
for (int x = vmin[0]; x <= vmax[0]; ++x)
{
int o = Offset(x, y, z);
if (_voxels[o] == null)
{
// Allocate new voxel and store primitive in it
_voxels[o] = new GridVoxel(_primitives[i]);
}
else
{
// Add primitive to already-allocated voxel
_voxels[o].AddPrimitive(_primitives[i]);
}
}
}
}
/// Creates a new bounding box padded by the given amount.
public static BBox Expand(BBox b, float delta)
{
return new BBox(
b.Min - new Vector(delta, delta, delta),
b.Max + new Vector(delta, delta, delta));
}
/// Creates a new bounding box large enough to contain the given two
/// bounding boxes.
public static BBox Union(BBox b1, BBox b2)
{
var min = new Point(Math.Min(b1.Min.X, b2.Min.X), Math.Min(b1.Min.Y, b2.Min.Y), Math.Min(b1.Min.Z, b2.Min.Z));
var max = new Point(Math.Max(b1.Max.X, b2.Max.X), Math.Max(b1.Max.Y, b2.Max.Y), Math.Max(b1.Max.Z, b2.Max.Z));
return new BBox(min, max);
}
/// Creates a new bounding box large enough to contain both the original
/// bounding box and the given point.
public static BBox Union(BBox b, Point p)
{
var min = new Point(Math.Min(b.Min.X, p.X), Math.Min(b.Min.Y, p.Y), Math.Min(b.Min.Z, p.Z));
var max = new Point(Math.Max(b.Max.X, p.X), Math.Max(b.Max.Y, p.Y), Math.Max(b.Max.Z, p.Z));
return new BBox(min, max);
}
public AggregateVolume(IEnumerable<VolumeRegion> regions)
{
_regions = regions.ToList();
_worldBound = BBox.Union(_regions.Select(x => x.WorldBound));
}
public BBox TransformBBox(BBox b)
{
var ret = BBox.FromPoint(TransformPoint(new Point(b.Min.X, b.Min.Y, b.Min.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Max.X, b.Min.Y, b.Min.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Min.X, b.Max.Y, b.Min.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Min.X, b.Min.Y, b.Max.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Min.X, b.Max.Y, b.Max.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Max.X, b.Max.Y, b.Min.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Max.X, b.Min.Y, b.Max.Z)));
ret = BBox.Union(ret, TransformPoint(new Point(b.Max.X, b.Max.Y, b.Max.Z)));
return ret;
}
/// Creates a new bounding box padded by the given amount.
public static BBox Expand(BBox b, float delta)
{
return(new BBox(
b.Min - new Vector(delta, delta, delta),
b.Max + new Vector(delta, delta, delta)));
}
