xfy/singularity-rs
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

shader: fix FBM disk seam (atan2→Cartesian) + value_noise3 range

Browse Source 
Two issues from code review: (1) the noise coordinate used phi=atan2
which has a branch-cut discontinuity at ±π, producing a visible radial
seam. Switch to Cartesian pos.x/pos.z (continuous, seam-free). (2)
value_noise3 summed three hash components per corner via dot(.,(1,1,1)),
giving a [-1.5,1.5) range instead of [0,1). Use a single scalar hash
(.x) per corner and drop the +0.5 recenter.
This commit is contained in:
xfy 2026-07-14 23:51:29 +08:00
parent f31ef900d8
commit 7d3a8a81ba
1 changed files with 10 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
assets/shaders/black_hole.wgsl
View File

@ -154,21 +154,21 @@ fn value_noise3(p: vec3<f32>) -> f32 {
let i = floor(p); let i = floor(p);
let f = fract(p); let f = fract(p);
let u = f * f * (3.0 - 2.0 * f); let u = f * f * (3.0 - 2.0 * f);
let n000 = dot(hash33(i + vec3<f32>(0.0, 0.0, 0.0)) - 0.5, vec3<f32>(1.0)); let n000 = hash33(i + vec3<f32>(0.0, 0.0, 0.0)).x;
let n100 = dot(hash33(i + vec3<f32>(1.0, 0.0, 0.0)) - 0.5, vec3<f32>(1.0)); let n100 = hash33(i + vec3<f32>(1.0, 0.0, 0.0)).x;
let n010 = dot(hash33(i + vec3<f32>(0.0, 1.0, 0.0)) - 0.5, vec3<f32>(1.0)); let n010 = hash33(i + vec3<f32>(0.0, 1.0, 0.0)).x;
let n110 = dot(hash33(i + vec3<f32>(1.0, 1.0, 0.0)) - 0.5, vec3<f32>(1.0)); let n110 = hash33(i + vec3<f32>(1.0, 1.0, 0.0)).x;
let n001 = dot(hash33(i + vec3<f32>(0.0, 0.0, 1.0)) - 0.5, vec3<f32>(1.0)); let n001 = hash33(i + vec3<f32>(0.0, 0.0, 1.0)).x;
let n101 = dot(hash33(i + vec3<f32>(1.0, 0.0, 1.0)) - 0.5, vec3<f32>(1.0)); let n101 = hash33(i + vec3<f32>(1.0, 0.0, 1.0)).x;
let n011 = dot(hash33(i + vec3<f32>(0.0, 1.0, 1.0)) - 0.5, vec3<f32>(1.0)); let n011 = hash33(i + vec3<f32>(0.0, 1.0, 1.0)).x;
let n111 = dot(hash33(i + vec3<f32>(1.0, 1.0, 1.0)) - 0.5, vec3<f32>(1.0)); let n111 = hash33(i + vec3<f32>(1.0, 1.0, 1.0)).x;
let nx00 = mix(n000, n100, u.x); let nx00 = mix(n000, n100, u.x);
let nx10 = mix(n010, n110, u.x); let nx10 = mix(n010, n110, u.x);
let nx01 = mix(n001, n101, u.x); let nx01 = mix(n001, n101, u.x);
let nx11 = mix(n011, n111, u.x); let nx11 = mix(n011, n111, u.x);
let nxy0 = mix(nx00, nx10, u.y); let nxy0 = mix(nx00, nx10, u.y);
let nxy1 = mix(nx01, nx11, u.y); let nxy1 = mix(nx01, nx11, u.y);
return mix(nxy0, nxy1, u.z) + 0.5; return mix(nxy0, nxy1, u.z);
} }
fn fbm3(p: vec3<f32>, octaves: u32) -> f32 { fn fbm3(p: vec3<f32>, octaves: u32) -> f32 {
@ -197,7 +197,7 @@ fn disk_color(pos: vec3<f32>, dir: vec3<f32>) -> vec3<f32> {
// Domain-warped FBM for feathered/smoky gas texture. The Keplerian shear // Domain-warped FBM for feathered/smoky gas texture. The Keplerian shear
// (rot ∝ 1/r^1.5) is folded into the noise flow term so inner radii flow // (rot ∝ 1/r^1.5) is folded into the noise flow term so inner radii flow
// faster than outer — correct differential rotation. // faster than outer — correct differential rotation.
let noise = disk_noise(vec3<f32>(r * 0.5, phi * 0.3, rot), uniforms.time); let noise = disk_noise(vec3<f32>(pos.x * 0.3, pos.z * 0.3, rot), uniforms.time);
let t = (r - uniforms.disk_inner) / (uniforms.disk_outer - uniforms.disk_inner); let t = (r - uniforms.disk_inner) / (uniforms.disk_outer - uniforms.disk_inner);
let tcol = mix(vec3<f32>(1.0, 0.95, 0.85), vec3<f32>(1.0, 0.45, 0.12), clamp(t, 0.0, 1.0)); let tcol = mix(vec3<f32>(1.0, 0.95, 0.85), vec3<f32>(1.0, 0.45, 0.12), clamp(t, 0.0, 1.0));