public bool RayCastStackless(int index)
{
LBVHNODE current = NativeNodes[0];
// Without using stack
float3 rayDirection = Rays[index].Direction;
// ----------------------------------------------------------------------------------------------------
float sA = rayDirection[current.SplitAxis];
current.NearNodeID = math.@select(current.LChildID, current.RChildID, sA < 0f);
current.FarNodeID = math.@select(current.RChildID, current.LChildID, sA < 0f);
// ----------------------------------------------------------------------------------------------------
int rootNearID = current.NearNodeID;
int rootNodeID = current.NodeID;
current = NativeNodes[rootNearID];
TraverseSstate state = TraverseSstate.FromParent;
bool intersect = false;
float bestDist = float.MaxValue;
while (current.NodeID != rootNodeID)
{
switch (state)
{
case TraverseSstate.FromChild:
int cID = current.NodeID;
current = NativeNodes[current.ParentID];
// ----------------------------------------------------------------------------------------------------
sA = rayDirection[current.SplitAxis];
current.NearNodeID = math.@select(current.LChildID, current.RChildID, sA < 0f);
current.FarNodeID = math.@select(current.RChildID, current.LChildID, sA < 0f);
// ----------------------------------------------------------------------------------------------------
if (cID == current.NearNodeID)
{
current = NativeNodes[current.FarNodeID];
state = TraverseSstate.FromSibling;
}
else
{
state = TraverseSstate.FromChild;
}
break;
case TraverseSstate.FromSibling:
if (!current.IntersectRay(Rays[index]))
{
current = NativeNodes[current.ParentID];
state = TraverseSstate.FromChild;
}
else if (current.IsLeaf == 1)
{
// No need to iterate as we can only have 1 triangle in a leaf node
if (NativePrims[current.PrimitivesOffset].IntersectRay(Rays[index], ref TempHi, index))
{
if (TempHi[index].HitDistance < bestDist)
{
bestDist = TempHi[index].HitDistance;
HitInfos[index] = TempHi[index];
intersect = true;
}
}
current = NativeNodes[current.ParentID];
state = TraverseSstate.FromChild;
}
else
{
// ----------------------------------------------------------------------------------------------------
sA = rayDirection[current.SplitAxis];
current.NearNodeID = math.@select(current.LChildID, current.RChildID, sA < 0f);
current.FarNodeID = math.@select(current.RChildID, current.LChildID, sA < 0f);
// ----------------------------------------------------------------------------------------------------
current = NativeNodes[current.NearNodeID];
state = TraverseSstate.FromParent;
}
break;
case TraverseSstate.FromParent:
if (!current.IntersectRay(Rays[index]))
{
cID = current.NodeID;
current = NativeNodes[current.ParentID];
// ----------------------------------------------------------------------------------------------------
sA = rayDirection[current.SplitAxis];
current.NearNodeID = math.@select(current.LChildID, current.RChildID, sA < 0f);
current.FarNodeID = math.@select(current.RChildID, current.LChildID, sA < 0f);
current = cID == current.NearNodeID ? NativeNodes[current.FarNodeID] : NativeNodes[current.NearNodeID];
state = TraverseSstate.FromSibling;
}
else if (current.IsLeaf == 1)
{
// No need to iterate as we can only have 1 triangle in a leaf node
if (NativePrims[current.PrimitivesOffset].IntersectRay(Rays[index], ref TempHi, index))
{
if (TempHi[index].HitDistance < bestDist)
{
bestDist = TempHi[index].HitDistance;
HitInfos[index] = TempHi[index];
intersect = true;
}
}
// ----------------------------------------------------------------------------------------------------
// ReSharper disable InlineOutVariableDeclaration
int lChild, rChild, splitAxis;
NativeNodes[current.ParentID].GetChildrenIDsAndSplitAxis(out lChild, out rChild, out splitAxis);
sA = rayDirection[splitAxis];
int farNodeID = math.@select(rChild, lChild, sA < 0f);
current = NativeNodes[farNodeID];
state = TraverseSstate.FromSibling;
}
else
{
// ----------------------------------------------------------------------------------------------------
sA = rayDirection[current.SplitAxis];
current.NearNodeID = math.@select(current.LChildID, current.RChildID, sA < 0f);
current.FarNodeID = math.@select(current.RChildID, current.LChildID, sA < 0f);
current = NativeNodes[current.NearNodeID];
state = TraverseSstate.FromParent;
}
break;
}
}
return(intersect);
}
public bool RayCastStackless(int index)
{
LBVHNODE current = NativeNodes[0];
float3 rayDirection = Rays[index].Direction;
// ----------------------------------------------------------------------------------------------------
float sA = rayDirection[current.SplitAxis];
current.NearNodeID = math.@select(current.LChildID, current.RChildID, sA < 0f);
current.FarNodeID = math.@select(current.RChildID, current.LChildID, sA < 0f);
// ----------------------------------------------------------------------------------------------------
int rootNearID = current.NearNodeID;
int rootNodeID = current.NodeID;
current = NativeNodes[rootNearID];
TraverseState state = TraverseState.FromParent;
bool intersect = false;
while (current.NodeID != rootNodeID)
{
switch (state)
{
case TraverseState.FromChild:
int cID = current.NodeID;
current = NativeNodes[current.ParentID];
// ----------------------------------------------------------------------------------------------------
sA = rayDirection[current.SplitAxis];
current.NearNodeID = math.@select(current.LChildID, current.RChildID, sA < 0f);
current.FarNodeID = math.@select(current.RChildID, current.LChildID, sA < 0f);
// ----------------------------------------------------------------------------------------------------
if (cID == current.NearNodeID)
{
current = NativeNodes[current.FarNodeID];
state = TraverseState.FromSibling;
}
else
{
state = TraverseState.FromChild;
}
break;
case TraverseState.FromSibling:
// ReSharper disable once NotAccessedVariable
float dist;
if (!BVHBBox.IntersectRay(Rays[index], current.BMin, current.BMax, out dist))
{
current = NativeNodes[current.ParentID];
state = TraverseState.FromChild;
}
else if (current.IsLeaf == 1)
{
if (NativePrims[current.PrimitivesOffset].IntersectRay(Rays[index], ref TempHi, index))
{
HitInfos.Add(TempHi[index]);
intersect = true;
}
current = NativeNodes[current.ParentID];
state = TraverseState.FromChild;
}
else
{
// ----------------------------------------------------------------------------------------------------
sA = rayDirection[current.SplitAxis];
current.NearNodeID = math.@select(current.LChildID, current.RChildID, sA < 0f);
current.FarNodeID = math.@select(current.RChildID, current.LChildID, sA < 0f);
// ----------------------------------------------------------------------------------------------------
current = NativeNodes[current.NearNodeID];
state = TraverseState.FromParent;
}
break;
case TraverseState.FromParent:
if (!BVHBBox.IntersectRay(Rays[index], current.BMin, current.BMax, out dist))
{
cID = current.NodeID;
current = NativeNodes[current.ParentID];
// ----------------------------------------------------------------------------------------------------
sA = rayDirection[current.SplitAxis];
current.NearNodeID = math.@select(current.LChildID, current.RChildID, sA < 0f);
current.FarNodeID = math.@select(current.RChildID, current.LChildID, sA < 0f);
// ----------------------------------------------------------------------------------------------------
if (cID == current.NearNodeID)
{
current = NativeNodes[current.FarNodeID];
state = TraverseState.FromSibling;
}
else
{
current = NativeNodes[current.NearNodeID];
state = TraverseState.FromSibling;
}
}
else if (current.IsLeaf == 1)
{
// Test triangle for intersection
if (NativePrims[current.PrimitivesOffset].IntersectRay(Rays[index], ref TempHi, index))
{
HitInfos.Add(TempHi[index]);
intersect = true;
}
// ----------------------------------------------------------------------------------------------------
int lChild, rChild, splitAxis;
NativeNodes[current.ParentID]
.GetChildrenIDsAndSplitAxis(out lChild, out rChild, out splitAxis);
sA = rayDirection[splitAxis];
//int nearNodeID = math.@select(lChild, rChild, sA < 0f);
int farNodeID = math.@select(rChild, lChild, sA < 0f);
// ----------------------------------------------------------------------------------------------------
current = NativeNodes[farNodeID];
state = TraverseState.FromSibling;
}
else
{
// ----------------------------------------------------------------------------------------------------
sA = rayDirection[current.SplitAxis];
current.NearNodeID = math.@select(current.LChildID, current.RChildID, sA < 0f);
current.FarNodeID = math.@select(current.RChildID, current.LChildID, sA < 0f);
// ----------------------------------------------------------------------------------------------------
current = NativeNodes[current.NearNodeID];
state = TraverseState.FromParent;
}
break;
}
}
return(intersect);
}
