#octree

[mangrovian]

Gradient town

[blenderfan1]

Testing the performance of different octree variants😄

New variants will be included in the next update of Gimme DOTS Geometry (update already scheduled)

[q39engine]

A multiresolution octree has several interrelated advantages over a uniform voxel grid when it comes to drawing isosurfaces. These two images (of the same model) show a situation that becomes much easier to render with a multiresolution framework: a case where you have an object with a relatively small geometric detail.

[fruitsoftheweb]

“View Dependent Octree Refinement”

[ravenkwok]

Testing stage during BTC’s development: Bézier curves set subdivision based on input RGB & depth sequences. 

[ravenkwok]

Testing stage during BTC’s development: octree structural subdivision + binding Bézier curves set subdivision + Free roam camera.

[ravenkwok]

Testing stage during BTC’s development: octree structural displacement.

[patrikpihlstrom]

No more Positions, and a few more Chunks

I'm going to go ahead and start this post exactly like I started my previous one.

Since my previous post, I've been working on:

Scaling down the overall memory usage of a voxel by removing the position, and replacing it with a function in the octree currently holding said voxel. This obviously meant that I had to rewrite a lot of my code, in order to manipulate voxels in any way. Among the changes lies a getPosition(index) function in the octree used to store the voxels. It looks something like this: x = (index%size%(size*size)); y = (index - x)/size%size; z = (index - x - size*y)/(size*size);

Finding new and exciting ways to divide the map =). Not really... Chunks are just convenient since they allow us to look at a set of voxels (at the moment 64*64*64), without having to worry about the rest of the map. They also allow us to easily send a certain set of voxels over the network. Basically, I moved the voxel octrees from the map object, to the chunk object, and created a vector of chunks within the map object. It's essentially just another layer of division. The most significant difference between a voxel octree, and a chunk is how a chunk stores it's position. It's just like a voxel in that regard. With an index, and a getPosition(index) function.

Bug fixing and optimizing(?)......... As expected, the mesher didn't like all of these changes, and I noticed a few bugs while I made said changes, and rewrote the mesher. Also, The division and distribution of voxels across child-trees is now faster, thanks to the lack of a position, since I had to figure out how to correctly distribute the voxels without checking for AABB-AABB intersection. By the way... Don't ever check for AABB-AABB intersection if you're going to populate an octree. Instead, iterate through all of the voxels for each eighth, and add them to their corresponding child-tree. for (x = 0, y = 0, z = 0; x < size/2; ++x)     for (y = 0, z = 0; y < size/2; ++y)         for (z = 0; z < size/2; ++z)             children[0]->voxels.push_back(getVoxel(x, y, z));

An image showing off the chunks: