metaballs/Assets/Scripts/CubeGrid.cs

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

struct GPUEdgeValues {
    public float edge0Val, edge1Val, edge2Val, edge3Val, edge4Val, edge5Val, edge6Val, edge7Val;
}

struct GPUPositions {
    public Vector3 edge0Pos, edge1Pos, edge2Pos, edge3Pos, edge4Pos, edge5Pos, edge6Pos, edge7Pos;
}

struct GPUBall {
    public float radiusSq;
    public Vector3 position;
}

public class CubeGrid {
    public List<Vector3> vertices;
    public int width, height, depth;
    public float resolution;

    private Container container;
    private Ball[] metaballs;
    private float threshold;

    private ComputeShader shader;
    private int shaderKernel;
    private GPUPositions[] precomputedPositions;
    private ComputeBuffer positionsBuffer;
    private ComputeBuffer outputBuffer;
    private ComputeBuffer metaballsBuffer;

    public const bool useGPU = true;

    public CubeGrid(Container container, float resolution, float threshold, ComputeShader shader, Ball[] metaballs) {
        this.width = Mathf.RoundToInt(container.transform.localScale.x / resolution);
        this.height = Mathf.RoundToInt(container.transform.localScale.y / resolution);
        this.depth = Mathf.RoundToInt(container.transform.localScale.z / resolution);

        this.vertices = new List<Vector3>();

        this.container = container;
        this.resolution = resolution;
        this.threshold = threshold;
        this.shader = shader;
        this.metaballs = metaballs;

        this.init();
    }

    public void evaluateAll() {
        this.vertices.Clear();

        if(CubeGrid.useGPU) {
            GPUBall[] gpuBalls = new GPUBall[this.metaballs.Length];

            for(int i = 0; i < this.metaballs.Length; i++) {
                Ball metaball = this.metaballs[i];
                gpuBalls[i].position = metaball.transform.localPosition;
                gpuBalls[i].radiusSq = metaball.radiusSq;
            }

            GPUEdgeValues[] edgeValues = this.runComputeShader(gpuBalls);

            for(int x = 0; x < this.width; x++) {
                for(int y = 0; y < this.height; y++) {
                    for(int z = 0; z < this.depth; z++) {
                        GPUEdgeValues edgeVal = edgeValues[x + this.width * (y + this.height * z)];
                        float[] edges = { edgeVal.edge0Val, edgeVal.edge1Val, edgeVal.edge2Val, edgeVal.edge3Val,
                            edgeVal.edge4Val, edgeVal.edge5Val, edgeVal.edge6Val, edgeVal.edge7Val};

                        this.updateVertices(edges, this.positionMap[x, y, z]);
                    }
                }
            }
        } else {
            for(int x = 0; x < this.width; x++) {
                for(int y = 0; y < this.height; y++) {
                    for(int z = 0; z < this.depth; z++) {
                        Vector3 relativePosition = this.positionMap[x, y, z];
                        float[] edges = this.evaluateCube(relativePosition);
                        this.updateVertices(edges, relativePosition);
                    }
                }
            }
        }
    }
    
    public int[] getTriangles() {
        int num = this.vertices.Count;

        if(this.triangleBuffer == null) {
            // nothing in buffer, create it
            this.triangleBuffer = new List<int>();
            for(int i = 0; i < num; i++) {
                this.triangleBuffer.Add(i);
            }

            return this.triangleBuffer.ToArray();
        } else if(this.triangleBuffer.Count < num) {
            // missing elements in buffer, add them
            for(int i = this.triangleBuffer.Count; i < num; i++) {
                this.triangleBuffer.Add(i);
            }

            return this.triangleBuffer.ToArray();
        } else if(this.triangleBuffer.Count == num) {
            // buffer is of perfect size, just return it

            return this.triangleBuffer.ToArray();
        } else {
            // buffer is too long, return slice

            return this.triangleBuffer.GetRange(0, num).ToArray();
        }
    }

    public void destroy() {
        this.positionsBuffer.Release();
        this.outputBuffer.Release();
        this.metaballsBuffer.Release();
        this.triangleBuffer = null;
    }

    //
    // Setup
    //

    private void init() {
        this.instantiateEdgeMap();
        this.instantiatePositionMap();

        if(CubeGrid.useGPU) {
            this.instantiateGPUPositions();
            this.instantiateComputeShader();
        }
    }

    private void instantiateEdgeMap() {
        this.edgeMap = new Vector3[] {
            new Vector3(-1, -1, -1),
            new Vector3(1, -1, -1),
            new Vector3(1, 1, -1),
            new Vector3(-1, 1, -1),
            new Vector3(-1, -1, 1),
            new Vector3(1, -1, 1),
            new Vector3(1, 1, 1),
            new Vector3(-1, 1, 1)
        };

        for(int i = 0; i < 8; i++) {
            this.edgeMap[i] /= 2;
            this.edgeMap[i] = new Vector3(this.edgeMap[i].x / ((float) this.width),
                this.edgeMap[i].y / ((float) this.height),
                this.edgeMap[i].z / ((float) this.depth));
        }
    }

    private void instantiatePositionMap() {
        this.positionMap = new Vector3[this.width, this.height, this.depth];

        for(int x = 0; x < this.width; x++) {
            for(int y = 0; y < this.height; y++) {
                for(int z = 0; z < this.depth; z++) {

                    float xCoord = (((float) x) / ((float) this.width)) - 0.5f;
                    float yCoord = (((float) y) / ((float) this.height)) - 0.5f;
                    float zCoord = (((float) z) / ((float) this.depth)) - 0.5f;

                    this.positionMap[x, y, z] = new Vector3(xCoord, yCoord, zCoord);
                }
            }
        }
    }

    private void instantiateGPUPositions() {
        this.precomputedPositions = new GPUPositions[this.width*this.height*this.depth];

        for(int x = 0; x < this.width; x++) {
            for(int y = 0; y < this.height; y++) {
                for(int z = 0; z < this.depth; z++) {
                    Vector3 centerPoint = this.positionMap[x, y, z];

                    this.precomputedPositions[x + this.width * (y + this.height * z)].edge0Pos = centerPoint + this.edgeMap[0];
                    this.precomputedPositions[x + this.width * (y + this.height * z)].edge1Pos = centerPoint + this.edgeMap[1];
                    this.precomputedPositions[x + this.width * (y + this.height * z)].edge2Pos = centerPoint + this.edgeMap[2];
                    this.precomputedPositions[x + this.width * (y + this.height * z)].edge3Pos = centerPoint + this.edgeMap[3];
                    this.precomputedPositions[x + this.width * (y + this.height * z)].edge4Pos = centerPoint + this.edgeMap[4];
                    this.precomputedPositions[x + this.width * (y + this.height * z)].edge5Pos = centerPoint + this.edgeMap[5];
                    this.precomputedPositions[x + this.width * (y + this.height * z)].edge6Pos = centerPoint + this.edgeMap[6];
                    this.precomputedPositions[x + this.width * (y + this.height * z)].edge7Pos = centerPoint + this.edgeMap[7];
                }
            }
        }
    }

    private void instantiateComputeShader() {
        this.positionsBuffer = new ComputeBuffer(this.precomputedPositions.Length, 96);
        this.positionsBuffer.SetData(this.precomputedPositions);

        this.outputBuffer = new ComputeBuffer(this.precomputedPositions.Length, 32);

        this.metaballsBuffer = new ComputeBuffer(this.precomputedPositions.Length, 16);

        this.shaderKernel = shader.FindKernel("Calculate");
        this.shader.SetBuffer(this.shaderKernel, "positions", this.positionsBuffer);
        this.shader.SetBuffer(this.shaderKernel, "outputBuffer", this.outputBuffer);

        this.shader.SetInt("width", this.width);
        this.shader.SetInt("height", this.height);
    }

    //
    // GPU metaball falloff function summator
    //

    private GPUEdgeValues[] runComputeShader(GPUBall[] gpuBalls) {
        this.metaballsBuffer.SetData(gpuBalls);
        this.shader.SetBuffer(this.shaderKernel, "metaballs", this.metaballsBuffer);

        this.shader.SetInt("numMetaballs", this.metaballs.Length);

        this.shader.Dispatch(this.shaderKernel, this.width / 8, this.height / 8, this.depth / 8);

        GPUEdgeValues[] output = new GPUEdgeValues[this.precomputedPositions.Length];
        this.outputBuffer.GetData(output);
        return output;
    }

    //
    // CPU metaball falloff function summator
    //

    private float[] evaluateCube(Vector3 centerPoint) {
        float[] edges = new float[8];

        for(int i = 0; i < 8; i++) {
            edges[i] = this.evaluatePoint(centerPoint + this.edgeMap[i]);
        }

        return edges;
    }

    private float evaluatePoint(Vector3 point) {
        float value = 0;

        foreach(Ball ball in this.metaballs) {
            Vector3 ballPosition = ball.transform.localPosition;
            float distX = point.x - ballPosition.x,
                distY = point.y - ballPosition.y,
                distZ = point.z - ballPosition.z;
            value += ball.radiusSq / (distX * distX + distY * distY + distZ * distZ);
        }

        return value;
    }

    //
    // Marching cubes algorithm
    //

    private void updateVertices(float[] edges, Vector3 relativePosition) {
        int cubeIndex = this.findIndex(edges);
        int pattern = this.edgeTable[cubeIndex];

        Vector3[] edgeVertices = new Vector3[12];

        for(int edge = 0; edge < 12; edge++) {
            if((pattern & 1 << edge) != 0) {
                int vertIndex0 = this.verticesAtEndsOfEdges[edge * 2];
                int vertIndex1 = this.verticesAtEndsOfEdges[edge * 2 + 1];

                float vertValue0 = edges[vertIndex0];
                float vertValue1 = edges[vertIndex1];

                Vector3 vertPosition0 = relativePosition + this.edgeMap[vertIndex0];
                Vector3 vertPosition1 = relativePosition + this.edgeMap[vertIndex1];

                float delta = (threshold - vertValue0) / (vertValue1 - vertValue0);

                // lineary interpolate positions
                edgeVertices[edge] = vertPosition0 + delta * (vertPosition1 - vertPosition0);
            }
        }

        for(int k = 0; triTable[cubeIndex][k] != -1; k += 3) {
            this.vertices.Add(edgeVertices[this.triTable[cubeIndex][k]]);
            this.vertices.Add(edgeVertices[this.triTable[cubeIndex][k + 2]]);
            this.vertices.Add(edgeVertices[this.triTable[cubeIndex][k + 1]]);
        }
    }

    private int findIndex(float[] edges) {
        byte cubeIndex = 0;

        if(edges[0] > this.threshold) {
            cubeIndex |= 1;
        }
        if(edges[1] > this.threshold) {
            cubeIndex |= 2;
        }
        if(edges[2] > this.threshold) {
            cubeIndex |= 4;
        }
        if(edges[3] > this.threshold) {
            cubeIndex |= 8;
        }
        if(edges[4] > this.threshold) {
            cubeIndex |= 16;
        }
        if(edges[5] > this.threshold) {
            cubeIndex |= 32;
        }
        if(edges[6] > this.threshold) {
            cubeIndex |= 64;
        }
        if(edges[7] > this.threshold) {
            cubeIndex |= 128;
        }

        // return index
        return cubeIndex;
    }

    //
    // LOOKUP TABLES
    //

    private List<int> triangleBuffer;

    private Vector3[,,] positionMap;

    private Vector3[] edgeMap;

    private int[] edgeTable = {
        0x0  , 0x109, 0x203, 0x30a, 0x406, 0x50f, 0x605, 0x70c,
        0x80c, 0x905, 0xa0f, 0xb06, 0xc0a, 0xd03, 0xe09, 0xf00,
        0x190, 0x99 , 0x393, 0x29a, 0x596, 0x49f, 0x795, 0x69c,
        0x99c, 0x895, 0xb9f, 0xa96, 0xd9a, 0xc93, 0xf99, 0xe90,
        0x230, 0x339, 0x33 , 0x13a, 0x636, 0x73f, 0x435, 0x53c,
        0xa3c, 0xb35, 0x83f, 0x936, 0xe3a, 0xf33, 0xc39, 0xd30,
        0x3a0, 0x2a9, 0x1a3, 0xaa , 0x7a6, 0x6af, 0x5a5, 0x4ac,
        0xbac, 0xaa5, 0x9af, 0x8a6, 0xfaa, 0xea3, 0xda9, 0xca0,
        0x460, 0x569, 0x663, 0x76a, 0x66 , 0x16f, 0x265, 0x36c,
        0xc6c, 0xd65, 0xe6f, 0xf66, 0x86a, 0x963, 0xa69, 0xb60,
        0x5f0, 0x4f9, 0x7f3, 0x6fa, 0x1f6, 0xff , 0x3f5, 0x2fc,
        0xdfc, 0xcf5, 0xfff, 0xef6, 0x9fa, 0x8f3, 0xbf9, 0xaf0,
        0x650, 0x759, 0x453, 0x55a, 0x256, 0x35f, 0x55 , 0x15c,
        0xe5c, 0xf55, 0xc5f, 0xd56, 0xa5a, 0xb53, 0x859, 0x950,
        0x7c0, 0x6c9, 0x5c3, 0x4ca, 0x3c6, 0x2cf, 0x1c5, 0xcc ,
        0xfcc, 0xec5, 0xdcf, 0xcc6, 0xbca, 0xac3, 0x9c9, 0x8c0,
        0x8c0, 0x9c9, 0xac3, 0xbca, 0xcc6, 0xdcf, 0xec5, 0xfcc,
        0xcc , 0x1c5, 0x2cf, 0x3c6, 0x4ca, 0x5c3, 0x6c9, 0x7c0,
        0x950, 0x859, 0xb53, 0xa5a, 0xd56, 0xc5f, 0xf55, 0xe5c,
        0x15c, 0x55 , 0x35f, 0x256, 0x55a, 0x453, 0x759, 0x650,
        0xaf0, 0xbf9, 0x8f3, 0x9fa, 0xef6, 0xfff, 0xcf5, 0xdfc,
        0x2fc, 0x3f5, 0xff , 0x1f6, 0x6fa, 0x7f3, 0x4f9, 0x5f0,
        0xb60, 0xa69, 0x963, 0x86a, 0xf66, 0xe6f, 0xd65, 0xc6c,
        0x36c, 0x265, 0x16f, 0x66 , 0x76a, 0x663, 0x569, 0x460,
        0xca0, 0xda9, 0xea3, 0xfaa, 0x8a6, 0x9af, 0xaa5, 0xbac,
        0x4ac, 0x5a5, 0x6af, 0x7a6, 0xaa , 0x1a3, 0x2a9, 0x3a0,
        0xd30, 0xc39, 0xf33, 0xe3a, 0x936, 0x83f, 0xb35, 0xa3c,
        0x53c, 0x435, 0x73f, 0x636, 0x13a, 0x33 , 0x339, 0x230,
        0xe90, 0xf99, 0xc93, 0xd9a, 0xa96, 0xb9f, 0x895, 0x99c,
        0x69c, 0x795, 0x49f, 0x596, 0x29a, 0x393, 0x99 , 0x190,
        0xf00, 0xe09, 0xd03, 0xc0a, 0xb06, 0xa0f, 0x905, 0x80c,
        0x70c, 0x605, 0x50f, 0x406, 0x30a, 0x203, 0x109, 0x0
    };

    private int[] verticesAtEndsOfEdges = {
        0,  1,
        1,  2,
        2,  3,
        3,  0,
        4,  5,
        5,  6,
        6,  7,
        7,  4,
        0,  4,
        1,  5,
        2,  6,
        3,  7
    };
    
    private int[][] triTable = {
        new int[] {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 8, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 1, 9, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 8, 3, 9, 8, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 2, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 8, 3, 1, 2, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 2, 10, 0, 2, 9, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {2, 8, 3, 2, 10, 8, 10, 9, 8, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 11, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 11, 2, 8, 11, 0, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 9, 0, 2, 3, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 11, 2, 1, 9, 11, 9, 8, 11, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 10, 1, 11, 10, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 10, 1, 0, 8, 10, 8, 11, 10, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 9, 0, 3, 11, 9, 11, 10, 9, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 8, 10, 10, 8, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 7, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 3, 0, 7, 3, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 1, 9, 8, 4, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 1, 9, 4, 7, 1, 7, 3, 1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 2, 10, 8, 4, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 4, 7, 3, 0, 4, 1, 2, 10, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 2, 10, 9, 0, 2, 8, 4, 7, -1, -1, -1, -1, -1, -1, -1},
        new int[] {2, 10, 9, 2, 9, 7, 2, 7, 3, 7, 9, 4, -1, -1, -1, -1},
        new int[] {8, 4, 7, 3, 11, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {11, 4, 7, 11, 2, 4, 2, 0, 4, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 0, 1, 8, 4, 7, 2, 3, 11, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 7, 11, 9, 4, 11, 9, 11, 2, 9, 2, 1, -1, -1, -1, -1},
        new int[] {3, 10, 1, 3, 11, 10, 7, 8, 4, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 11, 10, 1, 4, 11, 1, 0, 4, 7, 11, 4, -1, -1, -1, -1},
        new int[] {4, 7, 8, 9, 0, 11, 9, 11, 10, 11, 0, 3, -1, -1, -1, -1},
        new int[] {4, 7, 11, 4, 11, 9, 9, 11, 10, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 5, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 5, 4, 0, 8, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 5, 4, 1, 5, 0, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {8, 5, 4, 8, 3, 5, 3, 1, 5, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 2, 10, 9, 5, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 0, 8, 1, 2, 10, 4, 9, 5, -1, -1, -1, -1, -1, -1, -1},
        new int[] {5, 2, 10, 5, 4, 2, 4, 0, 2, -1, -1, -1, -1, -1, -1, -1},
        new int[] {2, 10, 5, 3, 2, 5, 3, 5, 4, 3, 4, 8, -1, -1, -1, -1},
        new int[] {9, 5, 4, 2, 3, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 11, 2, 0, 8, 11, 4, 9, 5, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 5, 4, 0, 1, 5, 2, 3, 11, -1, -1, -1, -1, -1, -1, -1},
        new int[] {2, 1, 5, 2, 5, 8, 2, 8, 11, 4, 8, 5, -1, -1, -1, -1},
        new int[] {10, 3, 11, 10, 1, 3, 9, 5, 4, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 9, 5, 0, 8, 1, 8, 10, 1, 8, 11, 10, -1, -1, -1, -1},
        new int[] {5, 4, 0, 5, 0, 11, 5, 11, 10, 11, 0, 3, -1, -1, -1, -1},
        new int[] {5, 4, 8, 5, 8, 10, 10, 8, 11, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 7, 8, 5, 7, 9, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 3, 0, 9, 5, 3, 5, 7, 3, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 7, 8, 0, 1, 7, 1, 5, 7, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 5, 3, 3, 5, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 7, 8, 9, 5, 7, 10, 1, 2, -1, -1, -1, -1, -1, -1, -1},
        new int[] {10, 1, 2, 9, 5, 0, 5, 3, 0, 5, 7, 3, -1, -1, -1, -1},
        new int[] {8, 0, 2, 8, 2, 5, 8, 5, 7, 10, 5, 2, -1, -1, -1, -1},
        new int[] {2, 10, 5, 2, 5, 3, 3, 5, 7, -1, -1, -1, -1, -1, -1, -1},
        new int[] {7, 9, 5, 7, 8, 9, 3, 11, 2, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 5, 7, 9, 7, 2, 9, 2, 0, 2, 7, 11, -1, -1, -1, -1},
        new int[] {2, 3, 11, 0, 1, 8, 1, 7, 8, 1, 5, 7, -1, -1, -1, -1},
        new int[] {11, 2, 1, 11, 1, 7, 7, 1, 5, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 5, 8, 8, 5, 7, 10, 1, 3, 10, 3, 11, -1, -1, -1, -1},
        new int[] {5, 7, 0, 5, 0, 9, 7, 11, 0, 1, 0, 10, 11, 10, 0, -1},
        new int[] {11, 10, 0, 11, 0, 3, 10, 5, 0, 8, 0, 7, 5, 7, 0, -1},
        new int[] {11, 10, 5, 7, 11, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {10, 6, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 8, 3, 5, 10, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 0, 1, 5, 10, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 8, 3, 1, 9, 8, 5, 10, 6, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 6, 5, 2, 6, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 6, 5, 1, 2, 6, 3, 0, 8, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 6, 5, 9, 0, 6, 0, 2, 6, -1, -1, -1, -1, -1, -1, -1},
        new int[] {5, 9, 8, 5, 8, 2, 5, 2, 6, 3, 2, 8, -1, -1, -1, -1},
        new int[] {2, 3, 11, 10, 6, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {11, 0, 8, 11, 2, 0, 10, 6, 5, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 1, 9, 2, 3, 11, 5, 10, 6, -1, -1, -1, -1, -1, -1, -1},
        new int[] {5, 10, 6, 1, 9, 2, 9, 11, 2, 9, 8, 11, -1, -1, -1, -1},
        new int[] {6, 3, 11, 6, 5, 3, 5, 1, 3, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 8, 11, 0, 11, 5, 0, 5, 1, 5, 11, 6, -1, -1, -1, -1},
        new int[] {3, 11, 6, 0, 3, 6, 0, 6, 5, 0, 5, 9, -1, -1, -1, -1},
        new int[] {6, 5, 9, 6, 9, 11, 11, 9, 8, -1, -1, -1, -1, -1, -1, -1},
        new int[] {5, 10, 6, 4, 7, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 3, 0, 4, 7, 3, 6, 5, 10, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 9, 0, 5, 10, 6, 8, 4, 7, -1, -1, -1, -1, -1, -1, -1},
        new int[] {10, 6, 5, 1, 9, 7, 1, 7, 3, 7, 9, 4, -1, -1, -1, -1},
        new int[] {6, 1, 2, 6, 5, 1, 4, 7, 8, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 2, 5, 5, 2, 6, 3, 0, 4, 3, 4, 7, -1, -1, -1, -1},
        new int[] {8, 4, 7, 9, 0, 5, 0, 6, 5, 0, 2, 6, -1, -1, -1, -1},
        new int[] {7, 3, 9, 7, 9, 4, 3, 2, 9, 5, 9, 6, 2, 6, 9, -1},
        new int[] {3, 11, 2, 7, 8, 4, 10, 6, 5, -1, -1, -1, -1, -1, -1, -1},
        new int[] {5, 10, 6, 4, 7, 2, 4, 2, 0, 2, 7, 11, -1, -1, -1, -1},
        new int[] {0, 1, 9, 4, 7, 8, 2, 3, 11, 5, 10, 6, -1, -1, -1, -1},
        new int[] {9, 2, 1, 9, 11, 2, 9, 4, 11, 7, 11, 4, 5, 10, 6, -1},
        new int[] {8, 4, 7, 3, 11, 5, 3, 5, 1, 5, 11, 6, -1, -1, -1, -1},
        new int[] {5, 1, 11, 5, 11, 6, 1, 0, 11, 7, 11, 4, 0, 4, 11, -1},
        new int[] {0, 5, 9, 0, 6, 5, 0, 3, 6, 11, 6, 3, 8, 4, 7, -1},
        new int[] {6, 5, 9, 6, 9, 11, 4, 7, 9, 7, 11, 9, -1, -1, -1, -1},
        new int[] {10, 4, 9, 6, 4, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 10, 6, 4, 9, 10, 0, 8, 3, -1, -1, -1, -1, -1, -1, -1},
        new int[] {10, 0, 1, 10, 6, 0, 6, 4, 0, -1, -1, -1, -1, -1, -1, -1},
        new int[] {8, 3, 1, 8, 1, 6, 8, 6, 4, 6, 1, 10, -1, -1, -1, -1},
        new int[] {1, 4, 9, 1, 2, 4, 2, 6, 4, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 0, 8, 1, 2, 9, 2, 4, 9, 2, 6, 4, -1, -1, -1, -1},
        new int[] {0, 2, 4, 4, 2, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {8, 3, 2, 8, 2, 4, 4, 2, 6, -1, -1, -1, -1, -1, -1, -1},
        new int[] {10, 4, 9, 10, 6, 4, 11, 2, 3, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 8, 2, 2, 8, 11, 4, 9, 10, 4, 10, 6, -1, -1, -1, -1},
        new int[] {3, 11, 2, 0, 1, 6, 0, 6, 4, 6, 1, 10, -1, -1, -1, -1},
        new int[] {6, 4, 1, 6, 1, 10, 4, 8, 1, 2, 1, 11, 8, 11, 1, -1},
        new int[] {9, 6, 4, 9, 3, 6, 9, 1, 3, 11, 6, 3, -1, -1, -1, -1},
        new int[] {8, 11, 1, 8, 1, 0, 11, 6, 1, 9, 1, 4, 6, 4, 1, -1},
        new int[] {3, 11, 6, 3, 6, 0, 0, 6, 4, -1, -1, -1, -1, -1, -1, -1},
        new int[] {6, 4, 8, 11, 6, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {7, 10, 6, 7, 8, 10, 8, 9, 10, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 7, 3, 0, 10, 7, 0, 9, 10, 6, 7, 10, -1, -1, -1, -1},
        new int[] {10, 6, 7, 1, 10, 7, 1, 7, 8, 1, 8, 0, -1, -1, -1, -1},
        new int[] {10, 6, 7, 10, 7, 1, 1, 7, 3, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 2, 6, 1, 6, 8, 1, 8, 9, 8, 6, 7, -1, -1, -1, -1},
        new int[] {2, 6, 9, 2, 9, 1, 6, 7, 9, 0, 9, 3, 7, 3, 9, -1},
        new int[] {7, 8, 0, 7, 0, 6, 6, 0, 2, -1, -1, -1, -1, -1, -1, -1},
        new int[] {7, 3, 2, 6, 7, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {2, 3, 11, 10, 6, 8, 10, 8, 9, 8, 6, 7, -1, -1, -1, -1},
        new int[] {2, 0, 7, 2, 7, 11, 0, 9, 7, 6, 7, 10, 9, 10, 7, -1},
        new int[] {1, 8, 0, 1, 7, 8, 1, 10, 7, 6, 7, 10, 2, 3, 11, -1},
        new int[] {11, 2, 1, 11, 1, 7, 10, 6, 1, 6, 7, 1, -1, -1, -1, -1},
        new int[] {8, 9, 6, 8, 6, 7, 9, 1, 6, 11, 6, 3, 1, 3, 6, -1},
        new int[] {0, 9, 1, 11, 6, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {7, 8, 0, 7, 0, 6, 3, 11, 0, 11, 6, 0, -1, -1, -1, -1},
        new int[] {7, 11, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {7, 6, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 0, 8, 11, 7, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 1, 9, 11, 7, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {8, 1, 9, 8, 3, 1, 11, 7, 6, -1, -1, -1, -1, -1, -1, -1},
        new int[] {10, 1, 2, 6, 11, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 2, 10, 3, 0, 8, 6, 11, 7, -1, -1, -1, -1, -1, -1, -1},
        new int[] {2, 9, 0, 2, 10, 9, 6, 11, 7, -1, -1, -1, -1, -1, -1, -1},
        new int[] {6, 11, 7, 2, 10, 3, 10, 8, 3, 10, 9, 8, -1, -1, -1, -1},
        new int[] {7, 2, 3, 6, 2, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {7, 0, 8, 7, 6, 0, 6, 2, 0, -1, -1, -1, -1, -1, -1, -1},
        new int[] {2, 7, 6, 2, 3, 7, 0, 1, 9, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 6, 2, 1, 8, 6, 1, 9, 8, 8, 7, 6, -1, -1, -1, -1},
        new int[] {10, 7, 6, 10, 1, 7, 1, 3, 7, -1, -1, -1, -1, -1, -1, -1},
        new int[] {10, 7, 6, 1, 7, 10, 1, 8, 7, 1, 0, 8, -1, -1, -1, -1},
        new int[] {0, 3, 7, 0, 7, 10, 0, 10, 9, 6, 10, 7, -1, -1, -1, -1},
        new int[] {7, 6, 10, 7, 10, 8, 8, 10, 9, -1, -1, -1, -1, -1, -1, -1},
        new int[] {6, 8, 4, 11, 8, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 6, 11, 3, 0, 6, 0, 4, 6, -1, -1, -1, -1, -1, -1, -1},
        new int[] {8, 6, 11, 8, 4, 6, 9, 0, 1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 4, 6, 9, 6, 3, 9, 3, 1, 11, 3, 6, -1, -1, -1, -1},
        new int[] {6, 8, 4, 6, 11, 8, 2, 10, 1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 2, 10, 3, 0, 11, 0, 6, 11, 0, 4, 6, -1, -1, -1, -1},
        new int[] {4, 11, 8, 4, 6, 11, 0, 2, 9, 2, 10, 9, -1, -1, -1, -1},
        new int[] {10, 9, 3, 10, 3, 2, 9, 4, 3, 11, 3, 6, 4, 6, 3, -1},
        new int[] {8, 2, 3, 8, 4, 2, 4, 6, 2, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 4, 2, 4, 6, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 9, 0, 2, 3, 4, 2, 4, 6, 4, 3, 8, -1, -1, -1, -1},
        new int[] {1, 9, 4, 1, 4, 2, 2, 4, 6, -1, -1, -1, -1, -1, -1, -1},
        new int[] {8, 1, 3, 8, 6, 1, 8, 4, 6, 6, 10, 1, -1, -1, -1, -1},
        new int[] {10, 1, 0, 10, 0, 6, 6, 0, 4, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 6, 3, 4, 3, 8, 6, 10, 3, 0, 3, 9, 10, 9, 3, -1},
        new int[] {10, 9, 4, 6, 10, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 9, 5, 7, 6, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 8, 3, 4, 9, 5, 11, 7, 6, -1, -1, -1, -1, -1, -1, -1},
        new int[] {5, 0, 1, 5, 4, 0, 7, 6, 11, -1, -1, -1, -1, -1, -1, -1},
        new int[] {11, 7, 6, 8, 3, 4, 3, 5, 4, 3, 1, 5, -1, -1, -1, -1},
        new int[] {9, 5, 4, 10, 1, 2, 7, 6, 11, -1, -1, -1, -1, -1, -1, -1},
        new int[] {6, 11, 7, 1, 2, 10, 0, 8, 3, 4, 9, 5, -1, -1, -1, -1},
        new int[] {7, 6, 11, 5, 4, 10, 4, 2, 10, 4, 0, 2, -1, -1, -1, -1},
        new int[] {3, 4, 8, 3, 5, 4, 3, 2, 5, 10, 5, 2, 11, 7, 6, -1},
        new int[] {7, 2, 3, 7, 6, 2, 5, 4, 9, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 5, 4, 0, 8, 6, 0, 6, 2, 6, 8, 7, -1, -1, -1, -1},
        new int[] {3, 6, 2, 3, 7, 6, 1, 5, 0, 5, 4, 0, -1, -1, -1, -1},
        new int[] {6, 2, 8, 6, 8, 7, 2, 1, 8, 4, 8, 5, 1, 5, 8, -1},
        new int[] {9, 5, 4, 10, 1, 6, 1, 7, 6, 1, 3, 7, -1, -1, -1, -1},
        new int[] {1, 6, 10, 1, 7, 6, 1, 0, 7, 8, 7, 0, 9, 5, 4, -1},
        new int[] {4, 0, 10, 4, 10, 5, 0, 3, 10, 6, 10, 7, 3, 7, 10, -1},
        new int[] {7, 6, 10, 7, 10, 8, 5, 4, 10, 4, 8, 10, -1, -1, -1, -1},
        new int[] {6, 9, 5, 6, 11, 9, 11, 8, 9, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 6, 11, 0, 6, 3, 0, 5, 6, 0, 9, 5, -1, -1, -1, -1},
        new int[] {0, 11, 8, 0, 5, 11, 0, 1, 5, 5, 6, 11, -1, -1, -1, -1},
        new int[] {6, 11, 3, 6, 3, 5, 5, 3, 1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 2, 10, 9, 5, 11, 9, 11, 8, 11, 5, 6, -1, -1, -1, -1},
        new int[] {0, 11, 3, 0, 6, 11, 0, 9, 6, 5, 6, 9, 1, 2, 10, -1},
        new int[] {11, 8, 5, 11, 5, 6, 8, 0, 5, 10, 5, 2, 0, 2, 5, -1},
        new int[] {6, 11, 3, 6, 3, 5, 2, 10, 3, 10, 5, 3, -1, -1, -1, -1},
        new int[] {5, 8, 9, 5, 2, 8, 5, 6, 2, 3, 8, 2, -1, -1, -1, -1},
        new int[] {9, 5, 6, 9, 6, 0, 0, 6, 2, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 5, 8, 1, 8, 0, 5, 6, 8, 3, 8, 2, 6, 2, 8, -1},
        new int[] {1, 5, 6, 2, 1, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 3, 6, 1, 6, 10, 3, 8, 6, 5, 6, 9, 8, 9, 6, -1},
        new int[] {10, 1, 0, 10, 0, 6, 9, 5, 0, 5, 6, 0, -1, -1, -1, -1},
        new int[] {0, 3, 8, 5, 6, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {10, 5, 6, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {11, 5, 10, 7, 5, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {11, 5, 10, 11, 7, 5, 8, 3, 0, -1, -1, -1, -1, -1, -1, -1},
        new int[] {5, 11, 7, 5, 10, 11, 1, 9, 0, -1, -1, -1, -1, -1, -1, -1},
        new int[] {10, 7, 5, 10, 11, 7, 9, 8, 1, 8, 3, 1, -1, -1, -1, -1},
        new int[] {11, 1, 2, 11, 7, 1, 7, 5, 1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 8, 3, 1, 2, 7, 1, 7, 5, 7, 2, 11, -1, -1, -1, -1},
        new int[] {9, 7, 5, 9, 2, 7, 9, 0, 2, 2, 11, 7, -1, -1, -1, -1},
        new int[] {7, 5, 2, 7, 2, 11, 5, 9, 2, 3, 2, 8, 9, 8, 2, -1},
        new int[] {2, 5, 10, 2, 3, 5, 3, 7, 5, -1, -1, -1, -1, -1, -1, -1},
        new int[] {8, 2, 0, 8, 5, 2, 8, 7, 5, 10, 2, 5, -1, -1, -1, -1},
        new int[] {9, 0, 1, 5, 10, 3, 5, 3, 7, 3, 10, 2, -1, -1, -1, -1},
        new int[] {9, 8, 2, 9, 2, 1, 8, 7, 2, 10, 2, 5, 7, 5, 2, -1},
        new int[] {1, 3, 5, 3, 7, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 8, 7, 0, 7, 1, 1, 7, 5, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 0, 3, 9, 3, 5, 5, 3, 7, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 8, 7, 5, 9, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {5, 8, 4, 5, 10, 8, 10, 11, 8, -1, -1, -1, -1, -1, -1, -1},
        new int[] {5, 0, 4, 5, 11, 0, 5, 10, 11, 11, 3, 0, -1, -1, -1, -1},
        new int[] {0, 1, 9, 8, 4, 10, 8, 10, 11, 10, 4, 5, -1, -1, -1, -1},
        new int[] {10, 11, 4, 10, 4, 5, 11, 3, 4, 9, 4, 1, 3, 1, 4, -1},
        new int[] {2, 5, 1, 2, 8, 5, 2, 11, 8, 4, 5, 8, -1, -1, -1, -1},
        new int[] {0, 4, 11, 0, 11, 3, 4, 5, 11, 2, 11, 1, 5, 1, 11, -1},
        new int[] {0, 2, 5, 0, 5, 9, 2, 11, 5, 4, 5, 8, 11, 8, 5, -1},
        new int[] {9, 4, 5, 2, 11, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {2, 5, 10, 3, 5, 2, 3, 4, 5, 3, 8, 4, -1, -1, -1, -1},
        new int[] {5, 10, 2, 5, 2, 4, 4, 2, 0, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 10, 2, 3, 5, 10, 3, 8, 5, 4, 5, 8, 0, 1, 9, -1},
        new int[] {5, 10, 2, 5, 2, 4, 1, 9, 2, 9, 4, 2, -1, -1, -1, -1},
        new int[] {8, 4, 5, 8, 5, 3, 3, 5, 1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 4, 5, 1, 0, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {8, 4, 5, 8, 5, 3, 9, 0, 5, 0, 3, 5, -1, -1, -1, -1},
        new int[] {9, 4, 5, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 11, 7, 4, 9, 11, 9, 10, 11, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 8, 3, 4, 9, 7, 9, 11, 7, 9, 10, 11, -1, -1, -1, -1},
        new int[] {1, 10, 11, 1, 11, 4, 1, 4, 0, 7, 4, 11, -1, -1, -1, -1},
        new int[] {3, 1, 4, 3, 4, 8, 1, 10, 4, 7, 4, 11, 10, 11, 4, -1},
        new int[] {4, 11, 7, 9, 11, 4, 9, 2, 11, 9, 1, 2, -1, -1, -1, -1},
        new int[] {9, 7, 4, 9, 11, 7, 9, 1, 11, 2, 11, 1, 0, 8, 3, -1},
        new int[] {11, 7, 4, 11, 4, 2, 2, 4, 0, -1, -1, -1, -1, -1, -1, -1},
        new int[] {11, 7, 4, 11, 4, 2, 8, 3, 4, 3, 2, 4, -1, -1, -1, -1},
        new int[] {2, 9, 10, 2, 7, 9, 2, 3, 7, 7, 4, 9, -1, -1, -1, -1},
        new int[] {9, 10, 7, 9, 7, 4, 10, 2, 7, 8, 7, 0, 2, 0, 7, -1},
        new int[] {3, 7, 10, 3, 10, 2, 7, 4, 10, 1, 10, 0, 4, 0, 10, -1},
        new int[] {1, 10, 2, 8, 7, 4, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 9, 1, 4, 1, 7, 7, 1, 3, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 9, 1, 4, 1, 7, 0, 8, 1, 8, 7, 1, -1, -1, -1, -1},
        new int[] {4, 0, 3, 7, 4, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {4, 8, 7, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 10, 8, 10, 11, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 0, 9, 3, 9, 11, 11, 9, 10, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 1, 10, 0, 10, 8, 8, 10, 11, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 1, 10, 11, 3, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 2, 11, 1, 11, 9, 9, 11, 8, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 0, 9, 3, 9, 11, 1, 2, 9, 2, 11, 9, -1, -1, -1, -1},
        new int[] {0, 2, 11, 8, 0, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {3, 2, 11, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {2, 3, 8, 2, 8, 10, 10, 8, 9, -1, -1, -1, -1, -1, -1, -1},
        new int[] {9, 10, 2, 0, 9, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {2, 3, 8, 2, 8, 10, 0, 1, 8, 1, 10, 8, -1, -1, -1, -1},
        new int[] {1, 10, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {1, 3, 8, 9, 1, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 9, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {0, 3, 8, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
        new int[] {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}
    };
}