storytold/spark
2
0
Fork 0
mirror of https://github.com/storytold/spark.git synced 2026-10-13 23:52:44 +00:00
Code Issues Packages Projects Releases Wiki Activity

Custom/extended splat encoding ranges, Premultiplied alpha for hyper-saturated colors (#134)

Browse Source 
* Externalized SparkRenderer.maxPixelRadius and .minAlpha settings. Added to documentation. Added to examples/editor under Debug folder, moved sort32 there.

* Added SplatEncoding concept, applied individually to SparkRenderer (rgbMin/Max, lnScaleMinMax), SplatMesh (additionally sh1Min/Max, sh2, sh3). Updated examples/editor to control settings via gui. Updated all related code to pipe along settings where needed.
Added SparkRenderer.premultipliedAlpha to control blend mode and enable hyper-saturated color contributions by default.

* Fix SplatLoader not passing along encoding. Complete renaming to splat encoding.
This commit is contained in:
Andreas Sundquist
2025-07-23 10:04:24 -07:00
committed by GitHub
parent f4b4522c56
commit f60c2b0cf9
19 changed files with 568 additions and 149 deletions
Download Patch File Download Diff File Expand all files Collapse all files
rust/spark-internal-rs/src/lib.rs
+3 -2
View File
@@ -82,6 +82,7 @@ pub fn raycast_splats(
near: f32, far: f32,
num_splats: u32, packed_splats: Uint32Array,
raycast_ellipsoid: bool,
ln_scale_min: f32, ln_scale_max: f32,
) -> Float32Array {
let mut distances = Vec::<f32>::new();
@@ -94,9 +95,9 @@ pub fn raycast_splats(
subarray.copy_to(subbuffer);
if raycast_ellipsoid {
raycast_ellipsoids(subbuffer, &mut distances, [origin_x, origin_y, origin_z], [dir_x, dir_y, dir_z], near, far);
raycast_ellipsoids(subbuffer, &mut distances, [origin_x, origin_y, origin_z], [dir_x, dir_y, dir_z], near, far, ln_scale_min, ln_scale_max);
} else {
raycast_spheres(subbuffer, &mut distances, [origin_x, origin_y, origin_z], [dir_x, dir_y, dir_z], near, far);
raycast_spheres(subbuffer, &mut distances, [origin_x, origin_y, origin_z], [dir_x, dir_y, dir_z], near, far, ln_scale_min, ln_scale_max);
}
base += chunk_size;
rust/spark-internal-rs/src/raycast.rs
+11 -21
View File
@@ -2,30 +2,19 @@ use half::f16;
const MIN_OPACITY: f32 = 0.1;
pub const LN_SCALE_MIN: f32 = -12.0;
pub const LN_SCALE_MAX: f32 = 9.0;
pub const LN_RESCALE: f32 = (LN_SCALE_MAX - LN_SCALE_MIN) / 254.0; // 1..=255
// pub fn encode_scale(scale: f32) -> u8 {
// if scale == 0.0 {
// 0
// } else {
// // Allow scales below LN_SCALE_MIN to be encoded as 0, which signifies a 2DGS
// ((scale.ln() - LN_SCALE_MIN) / LN_RESCALE + 1.0).clamp(0.0, 255.0).round() as u8
// }
// }
pub fn decode_scale(scale: u8) -> f32 {
pub fn decode_scale(scale: u8, ln_scale_min: f32, ln_scale_max: f32) -> f32 {
if scale == 0 {
0.0
} else {
(LN_SCALE_MIN + (scale - 1) as f32 * LN_RESCALE).exp()
let ln_scale_scale = (ln_scale_max - ln_scale_min) / 254.0;
(ln_scale_min + (scale - 1) as f32 * ln_scale_scale).exp()
}
}
pub fn raycast_spheres(
buffer: &[u32], distances: &mut Vec<f32>,
origin: [f32; 3], dir: [f32; 3], near: f32, far: f32,
ln_scale_min: f32, ln_scale_max: f32,
) {
let quad_a = vec3_dot(dir, dir);
@@ -36,7 +25,7 @@ pub fn raycast_spheres(
}
let origin = vec3_sub(origin, extract_center(packed));
let scale = extract_scale(packed);
let scale = extract_scale(packed, ln_scale_min, ln_scale_max);
// Model the Gsplat as a sphere for faster approximate raycasting
let radius = (scale[0] + scale[1] + scale[2]) / 3.0;
@@ -58,6 +47,7 @@ pub fn raycast_spheres(
pub fn raycast_ellipsoids(
buffer: &[u32], distances: &mut Vec<f32>,
origin: [f32; 3], dir: [f32; 3], near: f32, far: f32,
ln_scale_min: f32, ln_scale_max: f32,
) {
for packed in buffer.chunks(4) {
let opacity = ((packed[0] >> 24) as u8) as f32 / 255.0;
@@ -66,7 +56,7 @@ pub fn raycast_ellipsoids(
}
let origin = vec3_sub(origin, extract_center(packed));
let scale = extract_scale(packed);
let scale = extract_scale(packed, ln_scale_min, ln_scale_max);
let quat = extract_quat(packed);
let inv_quat = [-quat[0], -quat[1], -quat[2], quat[3]];
@@ -139,10 +129,10 @@ fn extract_center(packed: &[u32]) -> [f32; 3] {
[x, y, z]
}
fn extract_scale(packed: &[u32]) -> [f32; 3] {
let scale_x = decode_scale(packed[3] as u8);
let scale_y = decode_scale((packed[3] >> 8) as u8);
let scale_z = decode_scale((packed[3] >> 16) as u8);
fn extract_scale(packed: &[u32], ln_scale_min: f32, ln_scale_max: f32) -> [f32; 3] {
let scale_x = decode_scale(packed[3] as u8, ln_scale_min, ln_scale_max);
let scale_y = decode_scale((packed[3] >> 8) as u8, ln_scale_min, ln_scale_max);
let scale_z = decode_scale((packed[3] >> 16) as u8, ln_scale_min, ln_scale_max);
[scale_x, scale_y, scale_z]
}