bevy_pbr/light/
point_light.rs

1use bevy_render::view::Visibility;
2
3use super::*;
4
5/// A light that emits light in all directions from a central point.
6///
7/// Real-world values for `intensity` (luminous power in lumens) based on the electrical power
8/// consumption of the type of real-world light are:
9///
10/// | Luminous Power (lumen) (i.e. the intensity member) | Incandescent non-halogen (Watts) | Incandescent halogen (Watts) | Compact fluorescent (Watts) | LED (Watts) |
11/// |------|-----|----|--------|-------|
12/// | 200  | 25  |    | 3-5    | 3     |
13/// | 450  | 40  | 29 | 9-11   | 5-8   |
14/// | 800  | 60  |    | 13-15  | 8-12  |
15/// | 1100 | 75  | 53 | 18-20  | 10-16 |
16/// | 1600 | 100 | 72 | 24-28  | 14-17 |
17/// | 2400 | 150 |    | 30-52  | 24-30 |
18/// | 3100 | 200 |    | 49-75  | 32    |
19/// | 4000 | 300 |    | 75-100 | 40.5  |
20///
21/// Source: [Wikipedia](https://en.wikipedia.org/wiki/Lumen_(unit)#Lighting)
22#[derive(Component, Debug, Clone, Copy, Reflect)]
23#[reflect(Component, Default, Debug)]
24#[require(CubemapFrusta, CubemapVisibleEntities, Transform, Visibility)]
25pub struct PointLight {
26    /// The color of this light source.
27    pub color: Color,
28
29    /// Luminous power in lumens, representing the amount of light emitted by this source in all directions.
30    pub intensity: f32,
31
32    /// Cut-off for the light's area-of-effect. Fragments outside this range will not be affected by
33    /// this light at all, so it's important to tune this together with `intensity` to prevent hard
34    /// lighting cut-offs.
35    pub range: f32,
36
37    /// Simulates a light source coming from a spherical volume with the given
38    /// radius.
39    ///
40    /// This affects the size of specular highlights created by this light, as
41    /// well as the soft shadow penumbra size. Because of this, large values may
42    /// not produce the intended result -- for example, light radius does not
43    /// affect shadow softness or diffuse lighting.
44    pub radius: f32,
45
46    /// Whether this light casts shadows.
47    pub shadows_enabled: bool,
48
49    /// Whether soft shadows are enabled.
50    ///
51    /// Soft shadows, also known as *percentage-closer soft shadows* or PCSS,
52    /// cause shadows to become blurrier (i.e. their penumbra increases in
53    /// radius) as they extend away from objects. The blurriness of the shadow
54    /// depends on the [`PointLight::radius`] of the light; larger lights result
55    /// in larger penumbras and therefore blurrier shadows.
56    ///
57    /// Currently, soft shadows are rather noisy if not using the temporal mode.
58    /// If you enable soft shadows, consider choosing
59    /// [`ShadowFilteringMethod::Temporal`] and enabling temporal antialiasing
60    /// (TAA) to smooth the noise out over time.
61    ///
62    /// Note that soft shadows are significantly more expensive to render than
63    /// hard shadows.
64    #[cfg(feature = "experimental_pbr_pcss")]
65    pub soft_shadows_enabled: bool,
66
67    /// A bias used when sampling shadow maps to avoid "shadow-acne", or false shadow occlusions
68    /// that happen as a result of shadow-map fragments not mapping 1:1 to screen-space fragments.
69    /// Too high of a depth bias can lead to shadows detaching from their casters, or
70    /// "peter-panning". This bias can be tuned together with `shadow_normal_bias` to correct shadow
71    /// artifacts for a given scene.
72    pub shadow_depth_bias: f32,
73
74    /// A bias applied along the direction of the fragment's surface normal. It is scaled to the
75    /// shadow map's texel size so that it can be small close to the camera and gets larger further
76    /// away.
77    pub shadow_normal_bias: f32,
78
79    /// The distance from the light to near Z plane in the shadow map.
80    ///
81    /// Objects closer than this distance to the light won't cast shadows.
82    /// Setting this higher increases the shadow map's precision.
83    ///
84    /// This only has an effect if shadows are enabled.
85    pub shadow_map_near_z: f32,
86}
87
88impl Default for PointLight {
89    fn default() -> Self {
90        PointLight {
91            color: Color::WHITE,
92            // 1,000,000 lumens is a very large "cinema light" capable of registering brightly at Bevy's
93            // default "very overcast day" exposure level. For "indoor lighting" with a lower exposure,
94            // this would be way too bright.
95            intensity: 1_000_000.0,
96            range: 20.0,
97            radius: 0.0,
98            shadows_enabled: false,
99            shadow_depth_bias: Self::DEFAULT_SHADOW_DEPTH_BIAS,
100            shadow_normal_bias: Self::DEFAULT_SHADOW_NORMAL_BIAS,
101            shadow_map_near_z: Self::DEFAULT_SHADOW_MAP_NEAR_Z,
102            #[cfg(feature = "experimental_pbr_pcss")]
103            soft_shadows_enabled: false,
104        }
105    }
106}
107
108impl PointLight {
109    pub const DEFAULT_SHADOW_DEPTH_BIAS: f32 = 0.08;
110    pub const DEFAULT_SHADOW_NORMAL_BIAS: f32 = 0.6;
111    pub const DEFAULT_SHADOW_MAP_NEAR_Z: f32 = 0.1;
112}
bevy_pbr/light/point_light.rs

bevy_pbr/light/
point_light.rs
