Trying to fix everything

2024-10-15 21:35:52 +02:00
parent 62d6662ad1
commit 7623d647ee
17 changed files with 1540 additions and 1137 deletions
@@ -0,0 +1,966 @@
+import Common;
+import Bisector;
+import CBT;
+import Parameters;
+
+// Needs to be defined before including update_utilities
+struct BisectorGeometry
+{
+    float3 p[4];
+};
+
+// Possible splits
+static const uint64_t NO_SPLIT = 0x00;
+static const uint64_t CENTER_SPLIT = 0x01;
+static const uint64_t RIGHT_SPLIT = 0x02;
+static const uint64_t LEFT_SPLIT = 0x04;
+static const uint64_t RIGHT_DOUBLE_SPLIT = (CENTER_SPLIT | RIGHT_SPLIT);
+static const uint64_t LEFT_DOUBLE_SPLIT = (CENTER_SPLIT | LEFT_SPLIT);
+static const uint64_t TRIPLE_SPLIT = (CENTER_SPLIT | RIGHT_SPLIT | LEFT_SPLIT);
+
+// Split buffer slots
+static const uint64_t SPLIT_COUNTER = 0;
+static const uint64_t SIMPLIFY_COUNTER = 1;
+static const uint64_t CLASSIFY_COUNTER_OFFSET = 2;
+
+int ClassifyBisector(in BisectorGeometry tri, uint depth)
+{
+    // Check the triangle's visibility
+    float3 triNormal = normalize(cross(tri.p[2] - tri.p[1], tri.p[0] - tri.p[1]));
+    float3 triCenter = (tri.p[0] + tri.p[1] + tri.p[2]) / 3.0;
+    float3 viewDir = normalize(-triCenter);
+    float FdotV = dot(viewDir, pViewParams.cameraForward_WS.xyz);
+    float VdotN = dot(viewDir, triNormal);
+
+    // Here we don't use 0 as it introduces stability issues at grazing angles
+    if (FdotV < 0.0 && VdotN < -1e-3)
+        return BACK_FACE_CULLED;
+
+    // Compute the triangle's AABB
+    float3 aabbMin = float3(min(min(tri.p[0].x, tri.p[1].x), tri.p[2].x), min(min(tri.p[0].y, tri.p[1].y), tri.p[2].y), min(min(tri.p[0].z, tri.p[1].z), tri.p[2].z));
+    float3 aabbMax = float3(max(max(tri.p[0].x, tri.p[1].x), tri.p[2].x), max(max(tri.p[0].y, tri.p[1].y), tri.p[2].y), max(max(tri.p[0].z, tri.p[1].z), tri.p[2].z));
+
+    // First we do a frustum culling pass
+    //if (!FrustumAABBIntersect(_FrustumPlanes, aabbMin, aabbMax))
+    //    return FRUSTUM_CULLED;
+
+    // Project the points on screen
+    float4x4 viewProjectionMatrix = mul(pViewParams.projectionMatrix, pViewParams.viewMatrix);
+    float4 p0P = mul(viewProjectionMatrix, float4(tri.p[0], 1.0));
+    p0P.xy = p0P.xy / p0P.w;
+    p0P.xy = (p0P.xy * 0.5 + 0.5);
+
+    float4 p1P = mul(viewProjectionMatrix, float4(tri.p[1], 1.0));
+    p1P.xy = p1P.xy / p1P.w;
+    p1P.xy = (p1P.xy * 0.5 + 0.5);
+
+    float4 p2P = mul(viewProjectionMatrix, float4(tri.p[2], 1.0));
+    p2P.xy = p2P.xy / p2P.w;
+    p2P.xy = (p2P.xy * 0.5 + 0.5);
+
+    // 2D area of the triangle
+    // here we didn't reverse the sign of the y coordinate at projection time, but we simply adapted the area evaluation
+    // The same way we don't multiply by the screen size before, but after which is equivalent
+    float area = 0.5 * abs(p0P.x * (p2P.y - p1P.y) + p1P.x * (p0P.y - p2P.y) + p2P.x * (p1P.y - p0P.y));
+    area *= pViewParams.screenDimensions.x * pViewParams.screenDimensions.y;
+
+    // We over estimate the area at grazing angles
+    float areaOverestimation = lerp(2.0, 1.0, pow(VdotN, 0.2));
+    area *= areaOverestimation;
+
+    // If the triangle's area is bigger than the target size and the depth is not the maximal depth, subdivide
+    if (pParams.update.triangleSize < area && depth < pParams.update.maxSubdivisionDepth)
+    {
+        // If the area is really big, put it in high priority.
+        return BISECT_ELEMENT;
+    }
+    else if ((pParams.update.triangleSize * 0.5 > area) || (depth > pParams.update.maxSubdivisionDepth))
+    {
+        // Transform the parent's point
+        float4 p3P = mul(viewProjectionMatrix, float4(tri.p[3], 1.0));
+        p3P.xy = p3P.xy / p3P.w;
+        p3P.xy = (p3P.xy * 0.5 + 0.5);
+
+        // Evaluate the parent area
+        float areaParent = 0.5 * abs(p0P.x * (p2P.y - p3P.y) + p3P.x * (p0P.y - p2P.y) + p2P.x * (p3P.y - p0P.y));
+        areaParent *= pViewParams.screenDimensions.x * pViewParams.screenDimensions.y;
+        areaParent *= areaOverestimation;
+
+        // If the depth is too high (max depth changed) or the area is too 
+        return ((pParams.update.triangleSize >= areaParent ) || (depth > pParams.update.maxSubdivisionDepth)) ? TOO_SMALL : UNCHANGED_ELEMENT;
+    }
+    return UNCHANGED_ELEMENT;
+}
+
+void ResetBuffers()
+{
+    pParams.memoryBuffer[0] = 0;
+    pParams.memoryBuffer[1] = cbt_size() - bit_count_buffer();
+
+    pParams.classificationBuffer[SPLIT_COUNTER] = 0;
+    pParams.classificationBuffer[SIMPLIFY_COUNTER] = 0;
+
+    pParams.allocateBuffer[0] = 0;
+
+    pParams.propagateBuffer[0] = 0;
+    pParams.propagateBuffer[1] = 0;
+
+    pParams.simplifyBuffer[0] = 0;
+
+    pParams.indirectDrawBuffer[0] = 0;
+    pParams.indirectDrawBuffer[1] = 1;
+    pParams.indirectDrawBuffer[2] = 0;
+    pParams.indirectDrawBuffer[3] = 0;
+
+    pParams.indirectDrawBuffer[4] = 0;
+    pParams.indirectDrawBuffer[5] = 1;
+    pParams.indirectDrawBuffer[6] = 0;
+    pParams.indirectDrawBuffer[7] = 0;
+
+    pParams.indirectDrawBuffer[8] = 0;
+}
+
+void ClassifyElement(uint currentID, BisectorGeometry bis, uint totalNumElements, uint baseDepth)
+{
+    // Evaluate the depth of the element
+    uint64_t heapID = pParams.heapIDBuffer[currentID];
+    uint depth = HeapIDDepth(heapID);
+    BisectorData cbisectorData = pParams.bisectorDataBuffer[currentID];
+
+    // Reset some values
+    cbisectorData.subdivisionPattern = 0;
+    cbisectorData.bisectorState = UNCHANGED_ELEMENT;
+    cbisectorData.problematicNeighbor = INVALID_POINTER;
+    cbisectorData.flags = VISIBLE_BISECTOR;
+    
+    // Does this triangle intersect the circle?
+    int currentValidity = ClassifyBisector(bis, depth);
+    if (currentValidity > UNCHANGED_ELEMENT)
+    {
+        // This element should be bisected
+        uint targetSlot = 0;
+        cbisectorData.bisectorState = BISECT_ELEMENT;
+        InterlockedAdd(pParams.classificationBuffer[SPLIT_COUNTER], 1, targetSlot);
+        pParams.classificationBuffer[CLASSIFY_COUNTER_OFFSET + targetSlot] = currentID;
+
+    }
+    else
+        cbisectorData.flags = currentValidity >= TOO_SMALL ? VISIBLE_BISECTOR : 0;
+
+    // What's the validity of the father?
+    if (baseDepth != depth && currentValidity < UNCHANGED_ELEMENT)
+    {   
+        // Mark that it requires simplification
+        cbisectorData.bisectorState = SIMPLIFY_ELEMENT;
+
+        // Only register it if it has an even heapID, the odd ones will be processed by the even ones
+        if (heapID % 2 == 0)
+        {
+            uint targetSlot = 0;
+            InterlockedAdd(pParams.classificationBuffer[SIMPLIFY_COUNTER], 1, targetSlot);
+            pParams.classificationBuffer[CLASSIFY_COUNTER_OFFSET + totalNumElements + targetSlot] = currentID;
+        }
+    }
+
+    // Update the bisector data
+    pParams.bisectorDataBuffer[currentID] = cbisectorData;
+}
+
+void SplitElement(uint currentID, uint baseDepth)
+{
+    // Get the neighbors information
+    uint3 cNeighbors = pParams.neighboursBuffer[currentID].xyz;
+
+    // If there is a neighbor X
+    if (cNeighbors.x != INVALID_POINTER)
+    {
+        // This is on the path of it's neighbor X
+        uint3 xNeighbors = pParams.neighboursBuffer[cNeighbors.x].xyz;
+        if (xNeighbors.z == currentID && pParams.bisectorDataBuffer[cNeighbors.x].bisectorState != UNCHANGED_ELEMENT)
+            return;
+    }
+
+    // If there is a neighbor Y
+    if (cNeighbors.y != INVALID_POINTER)
+    {
+        // This is on the path of it's neighbor Y
+        uint3 yNeighbors = pParams.neighboursBuffer[cNeighbors.y].xyz;
+        if (yNeighbors.z == currentID && pParams.bisectorDataBuffer[cNeighbors.y].bisectorState != UNCHANGED_ELEMENT)
+            return;
+    }
+
+    // Depth of the current triangle
+    uint64_t heapID = pParams.heapIDBuffer[currentID];
+    uint currentDepth = HeapIDDepth(heapID);
+
+    // Compute the maximal required memory for this subdivision
+    int maxRequiredMemory = 2 * (currentDepth - baseDepth) - 1;
+
+    // Get the twin information
+    uint twinID = cNeighbors.z;
+
+    // This avoid the massive over-reservation and saves a bunch of artifacts
+    if (twinID == INVALID_POINTER)
+        maxRequiredMemory = 1;
+    else if (pParams.neighboursBuffer[twinID].z == currentID)
+        maxRequiredMemory = 2;
+
+    // Try to reserve
+    int remainingMemory;
+    InterlockedAdd(pParams.memoryBuffer[1], -maxRequiredMemory, remainingMemory);
+
+    // Did someone manage to sneak-in while we were trying to pick the memory, add it back and try again
+    if (remainingMemory < maxRequiredMemory)
+    {
+        // Then add back the required memory and stop
+        InterlockedAdd(pParams.memoryBuffer[1], maxRequiredMemory, remainingMemory);
+        return;
+    }
+
+    // Let's actually count the memory that we will be using
+    uint usedMemory = 1;
+    uint prevPattern;
+    InterlockedOr(pParams.bisectorDataBuffer[currentID].subdivisionPattern, CENTER_SPLIT, prevPattern);
+
+    // If this is not zero, it means an other neighbor went faster than us, we restore the memory and leave.
+    if (prevPattern != 0)
+    {
+        InterlockedAdd(pParams.memoryBuffer[1], maxRequiredMemory, remainingMemory);
+        return;
+    }
+
+    // Mark this for allocation
+    uint targetLocation = 0;
+    InterlockedAdd(pParams.allocateBuffer[0], 1, targetLocation);
+    pParams.allocateBuffer[1 + targetLocation] = currentID;
+
+    // While we're not done (up the tree or everything is subdivided properly)
+    bool done = false;
+    while (!done)
+    {
+        // If this neighbor is not allocated, we're done.
+        if (twinID == INVALID_POINTER)
+            break;
+
+        // Grab the bisector of the neighbor
+        uint64_t nHeapID = pParams.heapIDBuffer[twinID];
+        BisectorData nBisectorData = pParams.bisectorDataBuffer[twinID];
+        uint nDepth = HeapIDDepth(nHeapID);
+        uint3 nNeighbors = pParams.neighboursBuffer[twinID].xyz;
+
+        // If both triangles have the same depth
+        if (nDepth == currentDepth)
+        {
+            // Raised the center split
+            InterlockedOr(pParams.bisectorDataBuffer[twinID].subdivisionPattern, CENTER_SPLIT, prevPattern);
+
+            // Only account for it if it was not raised before.
+            if (prevPattern == 0)
+            {
+                // Mark this for allocation
+                uint targetLocation = 0;
+                InterlockedAdd(pParams.allocateBuffer[0], 1, targetLocation);
+                pParams.allocateBuffer[1 + targetLocation] = twinID;
+                usedMemory++;
+            }
+
+            // And we're done
+            done = true;
+        }
+        // If this node has already been subdivided, it means that we need to add the third subdivision and we're done
+        else
+        {
+            if (nNeighbors[0] == currentID)
+                InterlockedOr(pParams.bisectorDataBuffer[twinID].subdivisionPattern, RIGHT_DOUBLE_SPLIT, prevPattern);
+            else // if (nNeighbors[1] == currentID)
+                InterlockedOr(pParams.bisectorDataBuffer[twinID].subdivisionPattern, LEFT_DOUBLE_SPLIT, prevPattern);
+
+            if (prevPattern != 0)
+            {
+                usedMemory++;
+                done = true;
+            }
+            else
+            {
+                // Mark this for allocation
+                uint targetLocation = 0;
+                InterlockedAdd(pParams.allocateBuffer[0], 1, targetLocation);
+                pParams.allocateBuffer[1 + targetLocation] = twinID;
+                
+                // Account for two splits
+                usedMemory += 2;
+
+                // the new bisector that needs to be propagated
+                currentID = twinID;
+                currentDepth = nDepth;
+                twinID = pParams.neighboursBuffer[currentID].z;
+            }
+        }
+    }
+
+    // Add back the unused memory (in case)
+    InterlockedAdd(pParams.memoryBuffer[1], max(maxRequiredMemory - usedMemory, 0), remainingMemory);
+}
+
+void AllocateElement(uint currentID)
+{
+    // Load the bisector for this element
+    BisectorData bisectorData = pParams.bisectorDataBuffer[currentID];
+
+    // Does this guy need to be subdivided
+    if (bisectorData.subdivisionPattern != 0)
+    {
+        // How many bits do we need?
+        int numSlots = countbits(bisectorData.subdivisionPattern);
+
+        // Request the number of bits we need using an interlock add
+        uint firstBitIndex = 0;
+        InterlockedAdd(pParams.memoryBuffer[0], numSlots, firstBitIndex);
+
+        // llocate the bits we need
+        for (uint bitId = 0; bitId < numSlots; ++bitId)
+        {
+            uint index = decode_bit_complement(firstBitIndex + bitId);
+            bisectorData.indices[bitId] = index;
+        }
+
+        // Output 
+        pParams.bisectorDataBuffer[currentID] = bisectorData;
+    }
+}
+
+#define SUBLING0_ID 0
+#define SUBLING1_ID 1
+#define SUBLING2_ID 2
+void evaluate_neighbors(uint currentID, uint bisectorID, out uint resX, out uint resY)
+{
+    BisectorData nBisectorData = pParams.bisectorDataBuffer[bisectorID];
+    uint3 nNeighbors = pParams.neighboursBuffer[bisectorID].xyz;
+    if (nBisectorData.subdivisionPattern == 0x01)
+    {
+        resX = nBisectorData.indices[SUBLING0_ID];
+        resY = bisectorID;
+    }
+    else if (nBisectorData.subdivisionPattern == 0x03)
+    {
+        if (nNeighbors[0] == currentID)
+        {
+            resX = nBisectorData.indices[SUBLING1_ID];
+            resY = bisectorID;
+        }
+        else
+        {
+            resX = nBisectorData.indices[SUBLING0_ID];
+            resY = nBisectorData.indices[SUBLING1_ID];
+        }
+    }
+    else if (nBisectorData.subdivisionPattern == 0x05)
+    {
+        if (nNeighbors[1] == currentID)
+        {
+            resX = nBisectorData.indices[SUBLING1_ID];
+            resY = nBisectorData.indices[SUBLING0_ID];
+        }
+        else
+        {
+            resX = nBisectorData.indices[SUBLING0_ID];
+            resY = bisectorID;
+        }
+    }
+    else
+    {
+        if (nNeighbors[0] == currentID)
+        {
+            resX = nBisectorData.indices[SUBLING1_ID];
+            resY = bisectorID;
+        }
+        else if (nNeighbors[1] == currentID)
+        {
+            resX = nBisectorData.indices[SUBLING2_ID];
+            resY = nBisectorData.indices[SUBLING0_ID];
+        }
+        else
+        {
+            resX = nBisectorData.indices[SUBLING0_ID];
+            resY = nBisectorData.indices[SUBLING1_ID];
+        }
+    }
+}
+
+void BisectElement(uint currentID)
+{
+    // If this bisector is not allocated or not subdivided, stop right away
+    uint64_t baseHeapID = pParams.heapIDBuffer[currentID];
+    BisectorData cBisectorData = pParams.bisectorDataBuffer[currentID];
+    if (baseHeapID == 0 || cBisectorData.subdivisionPattern == NO_SPLIT)
+        return;
+
+    // Load the bisector data of the target triangle
+    uint currentSubdiv = cBisectorData.subdivisionPattern;
+
+    // neighbors of the parent
+    uint3 cNeighbors = pParams.neighboursBuffer[currentID].xyz;
+    uint p_n0 = cNeighbors[0];
+    uint p_n1 = cNeighbors[1];
+    uint p_n2 = cNeighbors[2];
+
+    // Get the main axis subdiv
+    uint siblingID0 = cBisectorData.indices[0];
+    uint siblingID1 = cBisectorData.indices[1];
+    uint siblingID2 = cBisectorData.indices[2];
+
+    // Simple subdivision (along the main axis)
+    if (currentSubdiv == CENTER_SPLIT)
+    {   
+        uint resX = INVALID_POINTER, resY = INVALID_POINTER;
+        if (p_n2 != INVALID_POINTER)
+            evaluate_neighbors(currentID, p_n2, resX, resY);
+
+        // Set the heap IDs
+        pParams.heapIDBuffer[currentID] = 2 * baseHeapID;
+        pParams.heapIDBuffer[siblingID0] = 2 * baseHeapID + 1;
+
+        // Update the neighbors
+        uint3 modifiedNeighbors;
+        modifiedNeighbors[0] = siblingID0;
+        modifiedNeighbors[1] = resX;
+        modifiedNeighbors[2] = p_n0;
+        pParams.neighboursOutputBuffer[currentID] = uint4(modifiedNeighbors, 0);
+        modifiedNeighbors[0] = resY;
+        modifiedNeighbors[1] = currentID;
+        modifiedNeighbors[2] = p_n1;
+        pParams.neighboursOutputBuffer[siblingID0] = uint4(modifiedNeighbors, 0);
+
+        // Keep track of the parent
+        BisectorData modifiedBisector = cBisectorData;
+        modifiedBisector.propagationID = currentID;
+
+        modifiedBisector.problematicNeighbor = INVALID_POINTER;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[currentID] = modifiedBisector;
+
+        modifiedBisector.problematicNeighbor = p_n1;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[siblingID0] = modifiedBisector;
+
+        // Mark this for propagation
+        uint targetLocation = 0;
+        InterlockedAdd(pParams.propagateBuffer[0], 1, targetLocation);
+        pParams.propagateBuffer[2 + targetLocation] = siblingID0;
+    }
+    else if (currentSubdiv == RIGHT_DOUBLE_SPLIT)
+    {
+        // Grab the bisector of the twin
+        uint res0X = INVALID_POINTER, res0Y = INVALID_POINTER;
+        evaluate_neighbors(currentID, p_n0, res0X, res0Y);
+
+        uint res1X = INVALID_POINTER, res1Y = INVALID_POINTER;
+        if (p_n2 != INVALID_POINTER)
+            evaluate_neighbors(currentID, p_n2, res1X, res1Y);
+
+        // Set the heap IDs
+        pParams.heapIDBuffer[currentID] = 4 * baseHeapID;
+        pParams.heapIDBuffer[siblingID0] = 2 * baseHeapID + 1;
+        pParams.heapIDBuffer[siblingID1] = 4 * baseHeapID + 1;
+
+        uint3 modifiedNeighbors;
+        modifiedNeighbors[0] = siblingID1;
+        modifiedNeighbors[1] = res0X;
+        modifiedNeighbors[2] = siblingID0;
+        pParams.neighboursOutputBuffer[currentID] = uint4(modifiedNeighbors, 0);
+        modifiedNeighbors[0] = res1Y;
+        modifiedNeighbors[1] = currentID;
+        modifiedNeighbors[2] = p_n1;
+        pParams.neighboursOutputBuffer[siblingID0] = uint4(modifiedNeighbors, 0);
+        modifiedNeighbors[0] = res0Y;
+        modifiedNeighbors[1] = currentID;
+        modifiedNeighbors[2] = res1X;
+        pParams.neighboursOutputBuffer[siblingID1] = uint4(modifiedNeighbors, 0);
+
+        // Keep track of the parent
+        BisectorData modifiedBisector = cBisectorData;
+        modifiedBisector.propagationID = currentID;
+
+        // Lower the element down the tree and update it's sibling
+        modifiedBisector.problematicNeighbor = INVALID_POINTER;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[currentID] = modifiedBisector;
+
+        // Create the sibling of the current element
+        modifiedBisector.problematicNeighbor = p_n1;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[siblingID0] = modifiedBisector;
+
+        // Create the sibling of the current element
+        modifiedBisector.problematicNeighbor = INVALID_POINTER;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[siblingID1] = modifiedBisector;
+
+        // Mark this for propagation
+        uint targetLocation = 0;
+        InterlockedAdd(pParams.propagateBuffer[0], 1, targetLocation);
+        pParams.propagateBuffer[2 + targetLocation] = siblingID0;
+    }
+    else if (currentSubdiv == LEFT_DOUBLE_SPLIT)
+    {
+        // Grab the bisector of the twin
+        uint res0X = INVALID_POINTER, res0Y = INVALID_POINTER;
+        evaluate_neighbors(currentID, p_n1, res0X, res0Y);
+
+        uint res1X = INVALID_POINTER, res1Y = INVALID_POINTER;
+        if (p_n2 != INVALID_POINTER)
+            evaluate_neighbors(currentID, p_n2, res1X, res1Y);
+
+        // Set the heap IDs
+        pParams.heapIDBuffer[currentID] = 2 * baseHeapID;
+        pParams.heapIDBuffer[siblingID0] = 4 * baseHeapID + 2;
+        pParams.heapIDBuffer[siblingID1] = 4 * baseHeapID + 3;
+
+        uint3 modifiedNeighbors;
+        modifiedNeighbors[0] = siblingID1;
+        modifiedNeighbors[1] = res1X;
+        modifiedNeighbors[2] = p_n0;
+        pParams.neighboursOutputBuffer[currentID] = uint4(modifiedNeighbors, 0);
+        modifiedNeighbors[0] = siblingID1;
+        modifiedNeighbors[1] = res0X;
+        modifiedNeighbors[2] = res1Y;
+        pParams.neighboursOutputBuffer[siblingID0] = uint4(modifiedNeighbors, 0);
+        modifiedNeighbors[0] = res0Y;
+        modifiedNeighbors[1] = siblingID0;
+        modifiedNeighbors[2] = currentID;
+        pParams.neighboursOutputBuffer[siblingID1] = uint4(modifiedNeighbors, 0);
+
+        // Keep track of the parent
+        BisectorData modifiedBisector = cBisectorData;
+        modifiedBisector.propagationID = currentID;
+
+        // Lower the element down the tree and update it's sibling
+        modifiedBisector.problematicNeighbor = INVALID_POINTER;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[currentID] = modifiedBisector;
+
+        // Create the sibling of the current element
+        modifiedBisector.problematicNeighbor = INVALID_POINTER;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[siblingID0] = modifiedBisector;
+
+        // Create the sibling of the current element
+        modifiedBisector.problematicNeighbor = INVALID_POINTER;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[siblingID1] = modifiedBisector;
+    }
+    else if (currentSubdiv == TRIPLE_SPLIT)
+    {
+        // Grab the bisector of the twin
+        uint res0X = INVALID_POINTER, res0Y = INVALID_POINTER;
+        evaluate_neighbors(currentID, p_n0, res0X, res0Y);
+
+        uint res1X = INVALID_POINTER, res1Y = INVALID_POINTER;
+        evaluate_neighbors(currentID, p_n1, res1X, res1Y);
+
+        uint res2X = INVALID_POINTER, res2Y = INVALID_POINTER;
+        if (p_n2 != INVALID_POINTER)
+            evaluate_neighbors(currentID, p_n2, res2X, res2Y);
+
+        // Set the heap IDs
+        pParams.heapIDBuffer[currentID] = 4 * baseHeapID;
+        pParams.heapIDBuffer[siblingID0] = 4 * baseHeapID + 2;
+        pParams.heapIDBuffer[siblingID1] = 4 * baseHeapID + 1;
+        pParams.heapIDBuffer[siblingID2] = 4 * baseHeapID + 3;
+
+        uint3 modifiedNeighbors;
+        modifiedNeighbors[0] = siblingID1;
+        modifiedNeighbors[1] = res0X;
+        modifiedNeighbors[2] = siblingID2;
+        pParams.neighboursOutputBuffer[currentID] = uint4(modifiedNeighbors, 0);
+        modifiedNeighbors[0] = siblingID2;
+        modifiedNeighbors[1] = res1X;
+        modifiedNeighbors[2] = res2Y;
+        pParams.neighboursOutputBuffer[siblingID0] = uint4(modifiedNeighbors, 0);
+        modifiedNeighbors[0] = res0Y;
+        modifiedNeighbors[1] = currentID;
+        modifiedNeighbors[2] = res2X;
+        pParams.neighboursOutputBuffer[siblingID1] = uint4(modifiedNeighbors, 0);
+        modifiedNeighbors[0] = res1Y;
+        modifiedNeighbors[1] = siblingID0;
+        modifiedNeighbors[2] = currentID;
+        pParams.neighboursOutputBuffer[siblingID2] = uint4(modifiedNeighbors, 0);
+
+        // Keep track of the parent
+        BisectorData modifiedBisector = cBisectorData;
+        modifiedBisector.propagationID = currentID;
+
+        // Lower the element down the tree and update it's sibling
+        modifiedBisector.problematicNeighbor = INVALID_POINTER;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[currentID] = modifiedBisector;
+
+        // Create the sibling of the current element
+        modifiedBisector.problematicNeighbor = INVALID_POINTER;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[siblingID0] = modifiedBisector;
+
+        // Create the sibling of the current element
+        modifiedBisector.problematicNeighbor = INVALID_POINTER;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[siblingID1] = modifiedBisector;
+
+        // Create the sibling of the current element
+        modifiedBisector.problematicNeighbor = INVALID_POINTER;
+        modifiedBisector.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[siblingID2] = modifiedBisector;
+    }
+
+    // How many bits do we need to raise
+    uint numSiblings = countbits(currentSubdiv);
+    for (uint siblingIdx = 0; siblingIdx < numSiblings; ++siblingIdx)
+    {
+        set_bit_atomic_buffer(cBisectorData.indices[siblingIdx], true);
+    }
+}
+
+void PropagateBisectElement(uint currentID)
+{
+    // Load the bisector data of the target triangle
+    BisectorData cBisectorData = pParams.bisectorDataBuffer[currentID];
+
+    // neighbors of the parent
+    uint parentID = cBisectorData.propagationID;
+    uint problematicNeighbor = cBisectorData.problematicNeighbor;
+
+    // Read the neighbor that may have changed
+    BisectorData tBisectorData = pParams.bisectorDataBuffer[problematicNeighbor];
+    uint3 tNeighbors = pParams.neighboursBuffer[problematicNeighbor].xyz;
+    uint targetID = problematicNeighbor;
+    uint sibling1 = tBisectorData.indices[1];
+
+    if (tBisectorData.subdivisionPattern == NO_SPLIT)
+    {
+        if (tNeighbors[0] == parentID)
+            pParams.neighboursBuffer[targetID][0] = currentID;
+        if (tNeighbors[1] == parentID)
+            pParams.neighboursBuffer[targetID][1] = currentID;
+        if (tNeighbors[2] == parentID)
+            pParams.neighboursBuffer[targetID][2] = currentID;
+    }
+    else if (tBisectorData.subdivisionPattern == CENTER_SPLIT)
+    {
+        if (pParams.neighboursBuffer[targetID][2] == parentID)
+            pParams.neighboursBuffer[targetID][2] = currentID;
+        if (pParams.neighboursBuffer[tBisectorData.propagationID][2] == parentID)
+            pParams.neighboursBuffer[tBisectorData.propagationID][2] = currentID;
+    }
+    else if (tBisectorData.subdivisionPattern == RIGHT_DOUBLE_SPLIT)
+    {
+        pParams.neighboursBuffer[sibling1][2] = currentID;
+    } 
+    else if (tBisectorData.subdivisionPattern == LEFT_DOUBLE_SPLIT)
+    {
+        pParams.neighboursBuffer[targetID][2] = currentID;
+    }
+
+    // Reset the problematic neighbor and the bisection state
+    pParams.bisectorDataBuffer[currentID].problematicNeighbor = INVALID_POINTER;
+    pParams.bisectorDataBuffer[currentID].bisectorState = UNCHANGED_ELEMENT;
+}
+
+void PrepareSimplifyElement(uint currentID)
+{
+    // Get the bisector
+    BisectorData cBisectorData = pParams.bisectorDataBuffer[currentID];
+
+    // Grab the current bisector
+    uint64_t cHeapID = pParams.heapIDBuffer[currentID];
+
+    // If this is not an even heap number it will be handeled by it's pair, the twin or the twin's pair
+
+    // Neighbors of this element
+    uint3 cNeighbors = pParams.neighboursBuffer[currentID].xyz;
+
+    // Evaluate the depth of this bisector
+    uint currentDepth = HeapIDDepth(cHeapID);
+
+    // Grab the pair neighbor (it has to exist)
+    uint pairID = cNeighbors[0];
+    uint64_t pHeapID = pParams.heapIDBuffer[pairID];
+    BisectorData pBisectorData = pParams.bisectorDataBuffer[pairID];
+    uint3 pNeighbors = pParams.neighboursBuffer[pairID].xyz;
+
+    // Evaluate the depth of the pair
+    uint pairDepth = HeapIDDepth(pHeapID);
+
+    // If they are not at the same depth or the pair is not to be simplified, we're done
+    if (pairDepth != currentDepth || pBisectorData.bisectorState != SIMPLIFY_ELEMENT)
+        return;
+
+    // We need to identify our twin pair
+    uint twinLowID = pNeighbors[0];
+    uint twinHighID = cNeighbors[1];
+    if (twinLowID != INVALID_POINTER)
+    {
+        // Grab the two bisectors
+        uint64_t twinLowHeapID = pParams.heapIDBuffer[twinLowID];
+        uint64_t twinHighHeapID = pParams.heapIDBuffer[twinHighID];
+        
+        // The current bisector is not the smallest element of the neighborhood, he will be handeled by twinLowBisect if needed
+        if (cHeapID > twinLowHeapID)
+            return;
+
+        // Compute the depth of both neighbors
+        uint lowFacingDepth = HeapIDDepth(twinLowHeapID);
+        uint highFacingDepth = HeapIDDepth(twinHighHeapID);
+
+        // If all four elements are not on the same
+        if (lowFacingDepth != currentDepth || highFacingDepth != currentDepth)
+            return;
+
+        // Grab the two bisectors
+        BisectorData twinLowBisectData = pParams.bisectorDataBuffer[twinLowID];
+        BisectorData twinHighBisectData = pParams.bisectorDataBuffer[twinHighID];
+
+        // This element should not be doing the simplifications if:
+        // - One of the four elements doesn't have the same depth
+        // - One of the four elements isn't flagged for simplification
+        if (twinLowBisectData.bisectorState != SIMPLIFY_ELEMENT
+            || twinHighBisectData.bisectorState != SIMPLIFY_ELEMENT)
+            return;
+    }
+
+    // This element will simplify itself, it's pair and possibilty it's twin and twin-pair.
+    uint bisectorSlot;
+    InterlockedAdd(pParams.simplifyBuffer[0], 1, bisectorSlot);
+
+    // Log the bisector ID
+    pParams.simplifyBuffer[1 + bisectorSlot] = currentID;
+}
+
+void SimplifyElement(uint currentID)
+{
+    // Grab the current bisector
+    BisectorData cBisectorData = pParams.bisectorDataBuffer[currentID];
+    uint3 cNeighbors = pParams.neighboursBuffer[currentID].xyz;
+
+    // Grab the pair neighbor (it has to exist)
+    uint pairID = cNeighbors[0];
+    BisectorData pBisectorData = pParams.bisectorDataBuffer[pairID];
+    uint3 pNeighbors = pParams.neighboursBuffer[pairID].xyz;
+
+    // We need to indentify our twin pair
+    uint twinLowID = pNeighbors[0];
+    uint twinHighID = cNeighbors[1];
+
+    // Set the heap IDs
+    pParams.heapIDBuffer[currentID] = pParams.heapIDBuffer[currentID] / 2;
+    pParams.heapIDBuffer[pairID] = 0;
+
+    // All conditions are met for us to simplify these triangles
+    uint3 newNeighbors;
+    newNeighbors[0] = cNeighbors[2];
+    newNeighbors[1] = pNeighbors[2];
+    newNeighbors[2] = twinLowID;
+    pParams.neighboursBuffer[currentID] = uint4(newNeighbors, 0);
+
+    // Update the bisector data
+    cBisectorData.propagationID = pairID;
+    cBisectorData.problematicNeighbor = pNeighbors[2];
+    cBisectorData.bisectorState = MERGED_ELEMENT;
+    cBisectorData.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+    pParams.bisectorDataBuffer[currentID] = cBisectorData;
+
+    // Mark this for propagation
+    if (cBisectorData.problematicNeighbor != INVALID_POINTER)
+    {
+        // Mark this for propagation
+        uint targetLocation = 0;
+        InterlockedAdd(pParams.propagateBuffer[1], 1, targetLocation);
+        pParams.propagateBuffer[2 + targetLocation] = currentID;
+    }
+
+    // Clear the pair's heap for identification
+    pBisectorData.bisectorState = MERGED_ELEMENT;
+    pBisectorData.flags = 0;
+    pParams.bisectorDataBuffer[pairID] = pBisectorData;
+
+    // Don't forget to free the bit
+    set_bit_atomic_buffer(pairID, false);
+
+    // If there was a facing pair, simplify it aswell
+    if (twinLowID != INVALID_POINTER)
+    {
+        // Set the heap IDs
+        pParams.heapIDBuffer[twinLowID] = pParams.heapIDBuffer[twinLowID] / 2;
+        pParams.heapIDBuffer[twinHighID] = 0;
+
+        // Read both bisectors
+        BisectorData lowFacingBst = pParams.bisectorDataBuffer[twinLowID];
+        uint3 lfNeighbors = pParams.neighboursBuffer[twinLowID].xyz;
+        BisectorData highFacingBst = pParams.bisectorDataBuffer[twinHighID];
+        uint3 hfNeighbors = pParams.neighboursBuffer[twinHighID].xyz;
+
+        // Update the lowest ID
+        newNeighbors[0] = lfNeighbors[2];
+        newNeighbors[1] = hfNeighbors[2];
+        newNeighbors[2] = currentID;
+        pParams.neighboursBuffer[twinLowID] = uint4(newNeighbors, 0);
+
+        // Update the twin bisector data
+        lowFacingBst.propagationID = twinHighID;
+        lowFacingBst.problematicNeighbor = hfNeighbors[2];
+        lowFacingBst.bisectorState = MERGED_ELEMENT;
+        lowFacingBst.flags = (VISIBLE_BISECTOR | MODIFIED_BISECTOR);
+        pParams.bisectorDataBuffer[twinLowID] = lowFacingBst;
+
+        if (lowFacingBst.problematicNeighbor != INVALID_POINTER)
+        {
+            // Mark this for propagation
+            uint targetLocation = 0;
+            InterlockedAdd(pParams.propagateBuffer[1], 1, targetLocation);
+            pParams.propagateBuffer[2 + targetLocation] = twinLowID;
+        }
+
+        // Clear the pair's heap for identification 
+        highFacingBst.bisectorState = MERGED_ELEMENT;
+        highFacingBst.flags = 0;
+        pParams.bisectorDataBuffer[twinHighID] = highFacingBst;
+
+        // Don't forget to free the bit
+        set_bit_atomic_buffer(twinHighID, false);
+    }
+}
+
+void PropagateElementSimplify(uint currentID)
+{
+    // Load the bisector data of the target element
+    BisectorData cBisectorData = pParams.bisectorDataBuffer[currentID];
+
+    // Id of the element before the simplification
+    uint deletedPair = cBisectorData.propagationID;
+
+    // neighbors of the parent
+    uint neighborID = cBisectorData.problematicNeighbor;
+
+    // Read the neighbor that may have changed
+    BisectorData nBisectorData = pParams.bisectorDataBuffer[neighborID];
+    uint3 nNeighbors = pParams.neighboursBuffer[neighborID].xyz;
+
+    // The neighbor has not changed, so we just need to make it point on currentID instead of the pair that was deleted
+    if (nBisectorData.bisectorState != MERGED_ELEMENT)
+    {
+        for (uint i = 0; i < 3; ++i)
+        {
+            if (nNeighbors[i] == deletedPair)
+                pParams.neighboursBuffer[neighborID][i] = currentID;
+        }
+    }
+    // The neighbor has had a simplification, so we need to update a different neighbor based on if it went up one depth in the tree or was deleted.
+    else if (nBisectorData.bisectorState == MERGED_ELEMENT)
+    {
+        // He still exist, but was simplified
+        if (pParams.heapIDBuffer[neighborID] != 0)
+        {
+            for (uint i = 0; i < 3; ++i)
+            {
+                if (nNeighbors[i] == deletedPair)
+                    pParams.neighboursBuffer[neighborID][i] = currentID;
+            }
+        }
+        // He is gone, we need to update his pair instead of him.
+        else
+        {
+            uint neighborPair = nNeighbors[1];
+            for (uint i = 0; i < 3; ++i)
+            {
+                if (pParams.neighboursBuffer[neighborPair][i] == deletedPair)
+                    pParams.neighboursBuffer[neighborPair][i] = currentID;
+            }
+        }
+    }
+
+    // Reset the problematic neighbor
+    pParams.bisectorDataBuffer[currentID].problematicNeighbor = INVALID_POINTER;
+}
+
+void BisectorElementIndexation(uint currentID)
+{
+    // Grab the current heap ID
+    uint64_t cHeapID = pParams.heapIDBuffer[currentID];
+
+    // Deallocated element, we don't care
+    if (cHeapID == 0)
+        return;
+
+    // Reserve a slot for this bisector
+    uint bisectorSlot;
+    InterlockedAdd(pParams.indirectDrawBuffer[0], 3, bisectorSlot);
+
+    // Keep track of it's global ID
+    pParams.bisectorIndicesBuffer[bisectorSlot / 3] = currentID;
+
+    // Load the bisector data of the target element
+    BisectorData cBisectorData = pParams.bisectorDataBuffer[currentID];
+    
+    // Is it visible?
+    if ((cBisectorData.flags & VISIBLE_BISECTOR) == 0)
+        return;
+
+    // Reserve a slot for this visible bisector
+    InterlockedAdd(pParams.indirectDrawBuffer[4], 3, bisectorSlot);
+
+    // Keep track of it's global ID
+    pParams.visibleBisectorIndices[bisectorSlot / 3] = currentID;
+
+    // Is it visible?
+    if ((cBisectorData.flags & MODIFIED_BISECTOR) == 0)
+        return;
+
+    // Reserve a slot for this visible bisector
+    InterlockedAdd(pParams.indirectDrawBuffer[8], 4, bisectorSlot);
+
+    // Keep track of it's global ID
+    pParams.modifiedBisectorIndices[bisectorSlot / 4] = currentID;
+}
+
+void ValidateBisector(uint currentID)
+{
+    // Grab the current heap ID
+    uint64_t cHeapID = pParams.heapIDBuffer[currentID];
+
+    // Deallocated element, we don't care
+    if (cHeapID == 0)
+        return;
+
+    // Load the bisector data of the target element
+    uint3 cNeighbors = pParams.neighboursBuffer[currentID].xyz;
+
+    bool failed = false;
+    uint targetNeighbor = INVALID_POINTER;
+    uint targetIdx = INVALID_POINTER;
+    for (uint i = 0; i < 3; ++i)
+    {
+        uint neighborID = cNeighbors[i];
+        if (neighborID != INVALID_POINTER)
+        {
+            bool found = false;
+            uint3 nNeighbors = pParams.neighboursBuffer[neighborID].xyz;
+            for (uint j = 0; j < 3; ++j)
+            {
+                if (nNeighbors[j] == currentID)
+                    found = true;
+            }
+            if (!found)
+            {
+                failed = true;
+                targetNeighbor = neighborID;
+                targetIdx = i;
+                break;
+            }
+        }
+    }
+    
+    // Notify the failure
+    if (failed)
+    {
+        uint prevValue;
+        InterlockedAdd(pParams.validationBuffer[0], 1, prevValue);
+    }    
+}