1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
// G-buffer shadow raymarching shader for CNN v3
// Pass 2: Reads depth from Pass 1, marches shadow rays toward lights,
// outputs shadow factor (1.0=lit, 0.0=shadow) to RGBA8Unorm render target (.r).
#include "common_uniforms"
#include "camera_common"
#include "math/sdf_shapes"
#include "render/raymarching_id"
@group(0) @binding(0) var<uniform> globals: GlobalUniforms;
@group(0) @binding(1) var<storage, read> object_data: ObjectsBuffer;
@group(0) @binding(2) var depth_tex: texture_depth_2d;
struct GBufLight {
direction: vec4f, // xyz = toward light (world space, normalized)
color: vec4f, // rgb = color, a = intensity
}
struct GBufLightsUniforms {
lights: array<GBufLight, 2>,
params: vec4f, // x = num_lights
}
@group(0) @binding(3) var<uniform> lights: GBufLightsUniforms;
// ---- SDF scene (proxy box per object in local space) ----
// Stub required by render/raymarching (shadow() / rayMarch() call df()).
fn df(p: vec3f) -> f32 { return MAX_RAY_LENGTH; }
// SDF of the full scene: proxy box for each object transformed to local space.
fn dfWithID(p: vec3f) -> RayMarchResult {
var res: RayMarchResult;
res.distance = MAX_RAY_LENGTH;
res.distance_max = MAX_RAY_LENGTH;
res.object_id = 0.0;
let n = u32(globals.params.x);
for (var i = 0u; i < n; i++) {
let obj = object_data.objects[i];
let lp = (obj.inv_model * vec4f(p, 1.0)).xyz;
let d = sdBox(lp, vec3f(1.0));
if (d < res.distance) {
res.distance = d;
res.object_id = f32(i + 1u);
}
}
return res;
}
// ---- Vertex: fullscreen triangle ----
@vertex
fn vs_main(@builtin(vertex_index) vid: u32) -> @builtin(position) vec4f {
let x = f32((vid & 1u) << 2u) - 1.0;
let y = f32((vid & 2u) << 1u) - 1.0;
return vec4f(x, y, 0.0, 1.0);
}
// ---- Fragment: shadow factor per pixel ----
@fragment
fn fs_main(@builtin(position) pos: vec4f) -> @location(0) vec4f {
let depth = textureLoad(depth_tex, vec2i(pos.xy), 0);
// Sky / background: fully lit.
if (depth >= 1.0) {
return vec4f(1.0);
}
// Reconstruct world-space position from NDC + depth.
let res = globals.resolution;
let ndc = vec2f(
(pos.x / res.x) * 2.0 - 1.0,
1.0 - (pos.y / res.y) * 2.0
);
let clip = globals.inv_view_proj * vec4f(ndc, depth, 1.0);
let world = clip.xyz / clip.w;
// Surface normal estimated from SDF gradient.
let nor = normalWithID(world);
let bias_pos = world + nor * 0.02;
// March shadow rays toward each light; take the darkest value.
var shadow_val = 1.0;
let num_lights = u32(lights.params.x);
for (var i = 0u; i < num_lights; i++) {
let ld = lights.lights[i].direction.xyz;
let s = shadowWithStoredDistance(bias_pos, ld, MAX_RAY_LENGTH);
shadow_val = min(shadow_val, s);
}
return vec4f(shadow_val, shadow_val, shadow_val, 1.0);
}
|
