# World 2D in HDR

2D that tonemaps and blooms with the 3D scene.

```{raw} html
<a class="example-run-button" href="../demos/features_3d_world_2d_in_hdr.html">▶ Run in browser</a>

```

**Tags:** `3d` `2d` `hdr` `post-processing` `bloom`

Demonstrates the N1 "2D in HDR" model: when post-processing is on, world-space 2D
(sprites / shapes / particles) renders INTO the HDR buffer before tonemap, so it
gets exposure, tonemap and bloom consistently with the 3D scene. Screen-space 2D
(HUD/UI) stays crisp post-tonemap at authored LDR. A per-node ``hdr`` override
forces a node either way.

What to look for:
  - The bright 2D star (a world-space Polygon2D with colour > 1) BLOOMS, just like
    an emissive 3D surface -- impossible before N1 (2D used to paste on flat).
  - The grey "auto" quad and the 3D cube darken/brighten TOGETHER as you change
    exposure (both go through tonemap).
  - The "hdr=False" quad keeps its exact authored colour at any exposure (the
    escape hatch for stylised flat 2D).
  - The HUD text stays crisp and fixed regardless of exposure (screen-space LDR).

Controls:
    Left / Right - Adjust tonemap exposure
    Space        - Cycle the demo quad's hdr override (auto / on / off) [desktop only]
    B            - Toggle bloom
    A / D        - Orbit camera
    Escape       - Quit

Run: uv run python examples/features/3d/world_2d_in_hdr.py

## Source

```{literalinclude} ../../examples/features/3d/world_2d_in_hdr.py
:language: python
:linenos:
```