//Creates VoxelGrids and saves them in the HashMap.
//Always creates a grid with size (block_generator_radius*2+1)^3
public void GenerateDenseVoxelGrids(Vector3Int gridcoords)
{
for (int z = gridcoords.z - generation_radius; z <= gridcoords.z + generation_radius; z++)
{
for (int y = gridcoords.y - generation_radius; y <= gridcoords.y + generation_radius; y++)
{
for (int x = gridcoords.x - generation_radius; x <= gridcoords.x + generation_radius; x++)
{
Vector3Int position = new Vector3Int(x, y, z);
if (!voxelblock_hash_table.ContainsKey(ToKey(position)))
{
GameObject g = Instantiate(dense_voxel_grid);
g.transform.parent = this.transform;
g.transform.localScale = new Vector3(1, 1, 1);
g.transform.localRotation = Quaternion.identity;
g.transform.localPosition = new Vector3(x, y, z);
g.name = "Dense_" + x + "_" + y + "_" + z;
DenseVoxelGrid dvg = g.GetComponent <DenseVoxelGrid>();
dvg.Render();
voxelblock_hash_table.Add(ToKey(position), g);
}
}
}
}
}
//Function to update each voxel within a voxel grid
public void UpdateDenseVoxelGrid(DenseVoxelGrid dvg, int current_update_frame)
{
//Only update if voxelgrid was not updated this frame
if (current_update_frame == dvg.last_update_frame)
{
return;
}
//Do for every voxel in the Grid:
for (int z = 0; z < dvg.grid_size.z; z++)
{
for (int y = 0; y < dvg.grid_size.y; y++)
{
for (int x = 0; x < dvg.grid_size.x; x++)
{
//Convert voxelgrid coordinates to world coordinates
Vector3 worldcoord = dvg.DenseGridCoordToWorldCoord(x, y, z);
//Retrieve corresponding pixel coordinates
Vector2Int pixelcoord = GetPixelFromCoords(worldcoord);
//Check if pixel is within camera image
if (pixelcoord.x >= 0 && pixelcoord.y >= 0 && pixelcoord.x < interface_.differenceImage.width && pixelcoord.y < interface_.differenceImage.height)
{
//Retrieve VoxelType from pixelcoords
VoxelType vt = GetVoxelType(pixelcoord);
//Only update value if it is green/red in the image
if (vt != VoxelType.EMPTY)
{
//Calculate the exact distance btw the camera and the voxel
float dist_exact = GetDistanceToCameraScreen(worldcoord);
//Calculate the measured distance btw the camera and the voxel
float dist_measured = GetMeasuredDistance(vt, pixelcoord);
bool out_of_range = false;
//Calculate the TSDF value of this voxel
float tsdf = GetTSDFValue(dist_exact, dist_measured, out out_of_range);
//If the voxel is out of range (last part of the tsdf), truncate, else update the voxel
if (!out_of_range)
{
dvg.active_count += UpdateVoxel(ref dvg.grid[x, y, z], tsdf, vt);
}
}
}
}
}
}
//Render the updated block
dvg.Render();
//Set current update frame in voxelgrid
dvg.last_update_frame = current_update_frame;
}
//Main Method to Update Voxel Value.
//Input:
//value - calculated from the TSD Function.
//x, y, z - grid coordinates of Voxel to update
//current_update_frame - this ensures that voxels only get updated once
//Main Method Called From Reconstruction Button or via online update
public void ReconstructScene()
{
Debug.Log("Reconstruction");
//Used to measure reconstruction time
var watch = System.Diagnostics.Stopwatch.StartNew();
//Step 1: Choose Pixels at Random and Project Point to 3D View
int width = interface_.differenceImage.width;
int height = interface_.differenceImage.height;
int ind = 0;
for (int i = 0; i < number_of_samples; i++)
{
VoxelType vt = VoxelType.EMPTY;
//1.1 Draw a Random Pixel from difference Image
Vector2Int pixel = new Vector2Int();
int overflow = 0;
//1.2 Check if pixel is not empty and repeat if necessary
while (vt == VoxelType.EMPTY && overflow < 1000)
{
pixel.x = (int)(Random.value * width);
pixel.y = (int)(Random.value * height);
vt = GetVoxelType(pixel);
overflow++;
}
//1.3 Calculate coordinates of voxel from pixel depth value
Vector3 voxelcoords = GetCoordsFromPixel(vt, pixel);
//1.4 Recieve DenseVoxelGrid at this position or create a new one if necessary
DenseVoxelGrid dvg = SVG.GetDenseVoxelGrid(voxelcoords);
//1.5 Update DenseVoxelGrid at this position by backprojecting all voxels
UpdateDenseVoxelGrid(dvg, update_frame);
ind++;
}
Debug.Log(ind + " Pixels found a surface");
//Step 3: Look for empty voxel blocks and remove them
SVG.RemoveEmptyVoxelGrids();
update_frame++;
//Display elapsed time
watch.Stop();
var elapsedMs = watch.ElapsedMilliseconds;
Debug.Log("Reconstruction took " + elapsedMs + "Milliseconds");
}
//Does not have to be called every time, can also run in background
//Removes all voxel Grids that do not contain any active voxels
public void RemoveEmptyVoxelGrids()
{
List <string> toRemove = new List <string>();
foreach (DictionaryEntry de in voxelblock_hash_table)
{
GameObject g = de.Value as GameObject;
DenseVoxelGrid dvg = g.GetComponent <DenseVoxelGrid>();
if (dvg.active_count == 0)
{
toRemove.Add(de.Key as string);
Destroy(g);
}
}
foreach (string s in toRemove)
{
voxelblock_hash_table.Remove(s);
}
}
