Flood Modes

Flood Modes let you apply the active tool to matching voxels quickly instead of editing them one by one.

The important difference is scope. 2D Flood Mode stays on one slice, while 3D Flood Mode can expand through the full voxel volume.

Why This Matters

Flood operations are fast, but they only feel predictable once you understand their scope.

The key question is whether the flood should stay on one slice or expand through the full voxel grid.

Use the flood mode based on how far the operation should reach.

2D Flood Mode

2D Flood Mode applies the active tool to similar voxels on a single plane.

Foxel starts at the clicked voxel and expands across neighboring voxels on the active plane while the data still matches the flood criteria.

When you hover over a voxel face, Foxel shows a planar cross that indicates the slice on which the flood operation will be performed.

Use 2D Flood Mode when you want to affect matching voxels on one slice without changing voxels behind it.

When To Use 2D Flood Mode

Use 2D Flood Mode for:

• Painting one planar region
• Selecting on a single slice
• Replacing matching voxels without affecting depth behind them
• Keeping the operation limited to the active plane

3D Flood Mode

3D Flood Mode applies the active tool to similar voxels throughout the voxel grid.

Foxel starts at the clicked voxel and expands through the volume while the data still matches the flood criteria.

Use 3D Flood Mode when you want to affect matching voxels throughout the full volume instead of staying on one slice.

When To Use 3D Flood Mode

Use 3D Flood Mode for:

• Selecting a whole 3D region
• Repainting connected parts
• Assigning materials to a full component in one step
• Replacing one matching color across the voxel grid when Contiguous is turned off

Contiguous Option

Both flood modes support the Contiguous option in the Toolbar.

Contiguous controls whether the flood affects only connected matching voxels or all matching voxels in the allowed scope.

Contiguous Enabled

With Contiguous enabled, only connected matching voxels are affected.

Foxel starts from the clicked voxel and expands through matching neighboring voxels.

Use this when you want the operation to stay within one connected region.

Contiguous Disabled

With Contiguous disabled, all matching voxels in the allowed scope are affected.

The allowed scope depends on the mode:

• In 2D Flood Mode, the scope is the active slice.
• In 3D Flood Mode, the scope is the full voxel grid.

This makes 3D Flood Mode with Contiguous turned off a fast way to replace one matching color throughout the voxel grid.

How To Choose

Use this rule:

• Use 2D Flood Mode when the edit should stay on one slice.
• Use 3D Flood Mode when the edit should expand through the voxel volume.
• Enable Contiguous when only connected matching voxels should be affected.
• Disable Contiguous when all matching voxels in the allowed scope should be affected.

What To Remember

• 2D Flood Mode stays on one slice.
• 3D Flood Mode expands through the full volume.
• Both modes start from the clicked voxel.
• Both modes use matching data as flood criteria.
• Contiguous changes whether only connected matching voxels are affected.
• With Contiguous disabled, the mode scope matters even more.
• 3D Flood Mode with Contiguous off is a fast full-grid color-replace workflow.