Jérôme Bousquié
65 lines
2.0 KiB
Markdown
65 lines
2.0 KiB
Markdown
# DoF (depth of field)
|
||
|
||
Depth of field simulates camera-lens behavior: objects at the **focus distance** are sharp,
|
||
everything else is progressively blurred (the cinematic "bokeh" look). DoF is a post-process
|
||
that operates on the HDR texture + depth buffer, before tone mapping.
|
||
|
||
> **Prerequisite**: like bloom, DoF reads the HDR texture (and the depth buffer for the
|
||
> focus/blur computation). Enable HDR together with it.
|
||
|
||
## Activation
|
||
|
||
DoF is opt-in through the builder. Without it, no DoF textures are allocated and the pipeline
|
||
cost is **zero**:
|
||
|
||
```rust
|
||
use wsg_lib::prelude::*;
|
||
|
||
let app = AppBuilder::new()
|
||
.with_hdr(ToneMapper::Aces)
|
||
.with_dof(DoFConfig::cinematic(4.0)) // sharp at 4.0 world units
|
||
.build()
|
||
.await?;
|
||
```
|
||
|
||
## `DoFConfig`
|
||
|
||
| Field | Type | Meaning |
|
||
|-------|------|---------|
|
||
| `focus_distance` | `f32` | World distance where the image is perfectly sharp |
|
||
| `aperture` | `f32` | Blur intensity (0.0–1.0, clamped). Scales the circle of confusion |
|
||
| `max_blur` | `f32` | Maximum blur radius in pixels (clamps the CoC) |
|
||
|
||
Presets:
|
||
|
||
```rust
|
||
DoFConfig::new(focus_distance, aperture, max_blur) // custom
|
||
DoFConfig::cinematic(focus_distance) // aperture 0.3, max blur 12 px (cutscenes)
|
||
DoFConfig::subtle(focus_distance) // aperture 0.1, max blur 8 px (gameplay)
|
||
```
|
||
|
||
## Runtime change
|
||
|
||
The `dof` example switches focus presets with the keys `1`–`4` (near / mid / far / infinity)
|
||
and follows the zoom:
|
||
|
||
```sh
|
||
cargo run -p wsg-lib --example dof
|
||
```
|
||
|
||
## Cost
|
||
|
||
- **Without DoF** (default): zero overhead — no textures, no pass.
|
||
- **With DoF**: 1 extra fullscreen pass + 2 intermediate textures (the bokeh buffer), before
|
||
tone mapping.
|
||
|
||
## Limitations (MVP)
|
||
|
||
- A single focus distance per frame (no per-pixel focus / rack-focus over time).
|
||
- The blur is a fixed-radius Gaussian scaled by the circle of confusion.
|
||
|
||
## Links
|
||
|
||
- [User README](../README.md) · [Bloom](bloom.md) · [HDR & tone mapping](hdr.md) · [Examples](../examples.md)
|
||
- [Root README](../../../README.md)
|