WIP / POC: Parameterized voxelizer

[pyrollo]

A POC for parameterized voxelizers

Idea

The (already discussed) idea is to merge multiple variants of a same task only differing by the way they voxelize models.

For example, renderSurfaces, renderLines, renderLines2d, renderPoints and renderPoints2d all does the same work: place something at a position resulting from a voxelizer. They all could be replaces by a place task with a voxelizer parameter (along with model selection and placeable parameters).

Status

This is a working example, with a lot of work still to be done. But the example works.

All existing voxelizers are usable:

• Points2d/3d
• Lines2d
• Surface2d
• ThickLines2d/3d

Two more have been added:

• To2d: a 2d voxelizer that wraps a 3d voxelizer and flattens its results (no deduplication, probably not doable)
• SetAltitude: a 3d voxelizer wrapping a 2d voxelizer and a heighmap, assigning heightmap altitude to each 2d voxel.

Reason

Because that's soo coool!

TODOS

1 - Have (sort of) scoped values

This is a bit out of scope but I already simplified some methods by adding a temporary Generation.current() that avoids to pass generation from class to class.

Code would be much simplified if usage of a scoped/global/static sort of variable (like current() method) could be generalized, not only in that PR but also:

• In parameters create() methods;
• In heightmapSpecs create() methods;
• In Voxelizers voxelize() method, by intrinsically filter out voxels outside current tile;

2 - Improve parameters syntax

Temporary POC syntax is:

    type: place
    models: ...
    voxels:
      type: setAltitude
      voxels:
        type: surface
      altitude: ground
    place: ...

This places 2d buildings surfaces on ground heightmaps.

We may have something more concise like;

    type: place
    models: ...
    voxels:
      addAltitude: ground
      to: surface
    place: ...

3 - Model values

Voxelizers could use model values as parameter (for example, for line thickness).

4 - World Model

If we had a built-in "world" model that covers the entire world, we could also get rid of renderHeightmap task and replace it by a place task on that world model.

This would work only if voxelize() method gives results limited to current tile (or it would return way too many results).

Self-checks

• The code has unit tests associated
• The code has Javadoc Comments associated
• Complex / Unexpected code is explained / justified with a small comment
• Relevant documentation inside the /docs folder has been updated
• All examples in examples/ work the same (or have been adapted if subject to changes in this PR)
• Git history is clean (each commit accomplish a single task and describe it accordingly)
• The texts have been proofread (documentation, error messages, logs, comments...)

[github-actions]

[Maven Build Status]

📑 Commit: 7ad32a5525fcfece334d0c58e6c2847784aad9a8
⌚️ Date: 2026-07-09T17:12:56 (CEST)
🛠️ Status: ✅ Success

📦 Download artifact: Generator.jar