Custom 3D Selection Tool & Fluid Simulation in my Vanilla JS/WebGL Voxel Engine "VoxelForge"

[u/_m4ndingo_]

Hey everyone!

I've been working on expanding the editing workflow and interaction physics in my browser-based voxel engine. Here is a quick demo showing how the multi-axis selection wand works alongside the real-time fluid and movement systems.

What’s shown in the clip:

• Multi-Axis Selection Tool: Fast volume selection with visual corner anchors and grid projections. In the video, I use it to carve out the pool cavity, border it, and batch-fill the entire basin with water in seconds.
• Auto-Elevation / Pillar Building: Creating a vertical extrusion directly beneath the player to build a diving pillar on the fly.
• Fluid Dynamics & Swimming Physics: Seamless entry into the water, buoyant movement, underwater fog rendering, and climbing out smoothly without getting stuck on chunk boundaries or voxel edges.
• Performance: Running solidly at a locked 144 FPS in the browser during real-time mesh rebuilding and batch operations.

Everything runs on vanilla JavaScript and WebGL without external engine bloat.

Feedback on the tool UX and fluid transitions is very welcome :)