# Placement modifiers

NTM modifiers for placed-feature positions and generation gates.

## Modifier types

The ordered `placement` array in `data/<namespace>/worldgen/placed_feature/<path>.json` selects each modifier by `type`.

| Type | Effect |
| - | - |
| [`hbm:light_blocking_height`](https://movblock.mov/ntm-next/wiki/world-generation/placement-modifiers/light_blocking_height.md) | Moves each position to the light-blocking terrain surface. |
| [`hbm:world_config`](https://movblock.mov/ntm-next/wiki/world-generation/placement-modifiers/world_config.md) | Passes while every named world-generation switch is enabled. |
| [`hbm:ore_host`](https://movblock.mov/ntm-next/wiki/world-generation/placement-modifiers/ore_host.md) (since NTM 1.0.3) | Skips an ore chain where its host cannot occur within reach. |