Jérôme Bousquié
2.0 KiB
2.0 KiB
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:
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:
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:
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.