Problems with 3D Array for Voxel Data
- by Sean M.
I'm trying to implement a voxel engine in C++ using OpenGL, and I've been working on the rendering of the world. In order to render, I have a 3D array of uint16's that hold that id of the block at the point. I also have a 3D array of uint8's that I am using to store the visibility data for that point, where each bit represents if a face is visible. I have it so the blocks render and all of the proper faces are hidden if needed, but all of the blocks are offset by a power of 2 from where they are stored in the array. So the block at [0][0][0] is rendered at (0, 0, 0), and the block at 11 is rendered at (1, 1, 1), but the block at [2][2][2] is rendered at (4, 4, 4) and the block at [3][3][3] is rendered at (8, 8, 8), and so on and so forth.
This is the result of drawing the above situation:
I'm still a little new to the more advanced concepts of C++, like triple pointers, which I'm using for the 3D array, so I think the error is somewhere in there. This is the code for creating the arrays:
uint16*** _blockData; //Contains a 3D array of uint16s that are the ids of the blocks in the region
uint8*** _visibilityData; //Contains a 3D array of bytes that hold the visibility data for the faces
//Allocate memory for the world data
_blockData = new uint16**[REGION_DIM];
for (int i = 0; i < REGION_DIM; i++)
{
_blockData[i] = new uint16*[REGION_DIM];
for (int j = 0; j < REGION_DIM; j++)
_blockData[i][j] = new uint16[REGION_DIM];
}
//Allocate memory for the visibility
_visibilityData = new uint8**[REGION_DIM];
for (int i = 0; i < REGION_DIM; i++)
{
_visibilityData[i] = new uint8*[REGION_DIM];
for (int j = 0; j < REGION_DIM; j++)
_visibilityData[i][j] = new uint8[REGION_DIM];
}
Here is the code used to create the block mesh for the region:
//Check if the positive x face is visible, this happens for every face
//Block::VERT_X_POS is just an array of non-transformed cube verts for one face
//These checks are in a triple loop, which goes over every place in the array
if (_visibilityData[x][y][z] & 0x01 > 0)
{
_vertexData->AddData(&(translateVertices(Block::VERT_X_POS, x, y, z)[0]), sizeof(Block::VERT_X_POS));
}
//This is a seperate method, not in the loop
glm::vec3* translateVertices(const glm::vec3 data[], uint16 x, uint16 y, uint16 z)
{
glm::vec3* copy = new glm::vec3[6];
memcpy(©, &data, sizeof(data));
for(int i = 0; i < 6; i++)
copy[i] += glm::vec3(x, -y, z); //Make +y go down instead
return copy;
}
I cannot see where the blocks may be getting offset by more than they should be, and certainly not why the offsets are a power of 2. Any help is greatly appreciated. Thanks.
