public ObiHeightFieldHandle GetOrCreateHeightField(TerrainData source)
        {
            ObiHeightFieldHandle handle;

            if (!handles.TryGetValue(source, out handle))
            {
                // Get the heighfield into a 1d array:
                int width  = source.heightmapResolution;
                int height = source.heightmapResolution;

                float[,] heights = source.GetHeights(0, 0, width, height);
                float[] buffer = new float[width * height];

                for (int y = 0; y < height; ++y)
                {
                    for (int x = 0; x < width; ++x)
                    {
                        buffer[y * width + x] = heights[y, x];
                    }
                }

                handle = new ObiHeightFieldHandle(source, headers.count);
                handles.Add(source, handle);
                headers.Add(new HeightFieldHeader(samples.count, buffer.Length));

                samples.AddRange(buffer);
            }

            return(handle);
        }
        public void AddConstraint(int[] indices, bool isExplicit)
        {
            RegisterConstraint();

            firstIndex.Add((int)particleIndices.count);
            numIndices.Add((int)indices.Length);
            explicitGroup.Add(isExplicit ? 1 : 0);
            particleIndices.AddRange(indices);
            materialParameters.AddRange(new float[] { 1, 1, 1, 1, 1 });
        }