vdb-js

JavaScript implementation of OpenVDB.

The idea is to keep the code as close as possible to the original source.

Usage

JavaScript

Set/get voxel (with cached access)

let vdb = require('vdb-js');
 
let grid = new vdb.Grid(-1);
let accessor = grid.getAccessor();
 
accessor.setValueOn([0, 0, 0], 42);
accessor.getValue([0, 0, 0]); // 42

Iterate over active voxels

accessor.setValueOn([2, 1, 0], 42);
accessor.setValueOn([845, 64, 242], 42);
accessor.setValueOn([1000, 200000, 4000], 42);
 
let counter = 0;
for (const voxel of grid.beginVoxelOn()) {
  counter++;
  console.log(voxel.value); // 42
}
 
console.log(counter); // 3

Ray intersection

let eye = new vdb.Vec3(0, -1, 0);
let direction = new vdb.Vec3(0, 1, 0);
let ray = new vdb.Ray(eye, direction);
 
let intersector = new vdb.VolumeRayIntersector(grid);
 
if (intersector.setIndexRay(ray)) {
  console.log('Ray intersects!');
}
 
let start = [0, -10, 0];
let end = [0, 10, 0];
let timeSpanRef = new vdb.TimeSpan(start, end);
 
intersector.marchUntilEnd(timeSpanRef);
 
console.log('first hit of active tile/leaf:', timeSpanRef.t0);
console.log('first hit of inactive tile or exit point of BBOX for leaf nodes:', timeSpanRef.t1);

TypeScript

import { Grid } from 'vdb-js';
 
const grid = new Grid(-1);
const accessor = grid.getAccessor();
 
accessor.setValueOn([0, 0, 0], 42);
accessor.getValue([0, 0, 0]); // 42

Limitations

Currently, only the following hard-coded tree structure/hierarchy is supported:

• InternalNode2.DIM = 256
• InternalNode1.DIM = 64
• LeafNode.DIM = 8

                        ─ ─┌┬┬┬──────────┬┬┬┐─ ─
                           |||| RootNode ||||
                        ─ ─└┴┴┴─────┬────┴┴┴┘─ ─
                          ┌─────────┴─────────┐
                          ▼                   ▼
                  ┌───────────────┐   ┌───────────────┐   ┌─ ─ ─
                  | InternalNode2 |   | InternalNode2 |   |
                  └───────┬───────┘   └───────┬───────┘   └─ ─ ─
                ┌─────────┴─────────┐         └─────────┐
                ▼                   ▼                   ▼
        ┌───────────────┐   ┌───────────────┐   ┌───────────────┐   ┌─ ─ ─
        | InternalNode1 |   | InternalNode1 |   | InternalNode1 |   |
        └───────┬───────┘   └───────┬───────┘   └───────┬───────┘   └─ ─ ─
      ┌─────────┴────┐             ┌┴─────────────┐     └────────┐
      ▼              ▼             ▼              ▼              ▼
┌──────────┐   ┌──────────┐   ┌──────────┐   ┌──────────┐   ┌──────────┐   ┌─ ─ ─
| LeafNode |   | LeafNode |   | LeafNode |   | LeafNode |   | LeafNode |   |
└──────────┘   └──────────┘   └──────────┘   └──────────┘   └──────────┘   └─ ─ ─

OpenVDB

• Origianl repo
• High-level summary of the terminology and basic components
• Cookbook with code examples
• Original paper from Ken Museth: VDB: High-Resolution Sparse Volumes with Dynamic Topology
• Ken Museth explaining VDB: OpenVDB: An Open Source Data Structure and Toolkit for High-Resolution Volumes
• VDB on GPU: Fast Fluid Simulations with Sparse Volumes on the GPU
• Raytracing Sparse Volumes with NVIDIA® GVDB in DesignWorks

Publish

1. npm login
2. yarn nx build vdb
3. cd ./dist/libs/vdb
4. npm publish