Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Fix Maya-exported rigs by not trying to topologically sort glTF nodes. #17641

Merged
merged 1 commit into from
Feb 2, 2025
Merged

Fix Maya-exported rigs by not trying to topologically sort glTF nodes. #17641

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions crates/bevy_gltf/Cargo.toml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -59,6 +59,8 @@ gltf = { version = "1.4.0", default-features = false, features = [
] }
thiserror = { version = "2", default-features = false }
base64 = "0.22.0"
fixedbitset = "0.5"
itertools = "0.13"
percent-encoding = "2.1"
serde = { version = "1.0", features = ["derive"] }
serde_json = "1"
Expand Down
183 changes: 72 additions & 111 deletions crates/bevy_gltf/src/loader.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,7 +3,6 @@ use crate::{
GltfMaterialName, GltfMeshExtras, GltfNode, GltfSceneExtras, GltfSkin,
};

use alloc::collections::VecDeque;
use bevy_asset::{
io::Reader, AssetLoadError, AssetLoader, Handle, LoadContext, ReadAssetBytesError,
};
Expand Down Expand Up @@ -42,6 +41,7 @@ use bevy_scene::Scene;
#[cfg(not(target_arch = "wasm32"))]
use bevy_tasks::IoTaskPool;
use bevy_transform::components::Transform;
use fixedbitset::FixedBitSet;
use gltf::{
accessor::Iter,
image::Source,
Expand All @@ -50,6 +50,7 @@ use gltf::{
texture::{Info, MagFilter, MinFilter, TextureTransform, WrappingMode},
Document, Material, Node, Primitive, Semantic,
};
use itertools::Itertools;
use serde::{Deserialize, Serialize};
#[cfg(any(
feature = "pbr_specular_textures",
Expand Down Expand Up @@ -793,13 +794,36 @@ async fn load_gltf<'a, 'b, 'c>(
let mut named_nodes = <HashMap<_, _>>::default();
let mut skins = vec![];
let mut named_skins = <HashMap<_, _>>::default();
for node in GltfTreeIterator::try_new(&gltf)? {

// First, create the node handles.
for node in gltf.nodes() {
let label = GltfAssetLabel::Node(node.index());
let label_handle = load_context.get_label_handle(label.to_string());
nodes.insert(node.index(), label_handle);
}

// Then check for cycles.
check_gltf_for_cycles(&gltf)?;

// Now populate the nodes.
for node in gltf.nodes() {
let skin = node.skin().map(|skin| {
let joints = skin
let joints: Vec<_> = skin
.joints()
.map(|joint| nodes.get(&joint.index()).unwrap().clone())
.collect();

if joints.len() > MAX_JOINTS {
warn!(
"The glTF skin {} has {} joints, but the maximum supported is {}",
skin.name()
.map(ToString::to_string)
.unwrap_or_else(|| skin.index().to_string()),
joints.len(),
MAX_JOINTS
);
}

let gltf_skin = GltfSkin::new(
&skin,
joints,
Expand Down Expand Up @@ -1904,114 +1928,6 @@ async fn load_buffers(
Ok(buffer_data)
}

/// Iterator for a Gltf tree.
///
/// It resolves a Gltf tree and allows for a safe Gltf nodes iteration,
/// putting dependent nodes before dependencies.
struct GltfTreeIterator<'a> {
nodes: Vec<Node<'a>>,
}

impl<'a> GltfTreeIterator<'a> {
#[expect(
clippy::result_large_err,
reason = "`GltfError` is only barely past the threshold for large errors."
)]
fn try_new(gltf: &'a gltf::Gltf) -> Result<Self, GltfError> {
let nodes = gltf.nodes().collect::<Vec<_>>();

let mut empty_children = VecDeque::new();
let mut parents = vec![None; nodes.len()];
let mut unprocessed_nodes = nodes
.into_iter()
.enumerate()
.map(|(i, node)| {
let children = node
.children()
.map(|child| child.index())
.collect::<HashSet<_>>();
for &child in &children {
let parent = parents.get_mut(child).unwrap();
*parent = Some(i);
}
if children.is_empty() {
empty_children.push_back(i);
}
(i, (node, children))
})
.collect::<HashMap<_, _>>();

let mut nodes = Vec::new();
let mut warned_about_max_joints = <HashSet<_>>::default();
while let Some(index) = empty_children.pop_front() {
if let Some(skin) = unprocessed_nodes.get(&index).unwrap().0.skin() {
if skin.joints().len() > MAX_JOINTS && warned_about_max_joints.insert(skin.index())
{
warn!(
"The glTF skin {} has {} joints, but the maximum supported is {}",
skin.name()
.map(ToString::to_string)
.unwrap_or_else(|| skin.index().to_string()),
skin.joints().len(),
MAX_JOINTS
);
}

let skin_has_dependencies = skin
.joints()
.any(|joint| unprocessed_nodes.contains_key(&joint.index()));

if skin_has_dependencies && unprocessed_nodes.len() != 1 {
empty_children.push_back(index);
continue;
}
}

let (node, children) = unprocessed_nodes.remove(&index).unwrap();
assert!(children.is_empty());
nodes.push(node);

if let Some(parent_index) = parents[index] {
let (_, parent_children) = unprocessed_nodes.get_mut(&parent_index).unwrap();

assert!(parent_children.remove(&index));
if parent_children.is_empty() {
empty_children.push_back(parent_index);
}
}
}

if !unprocessed_nodes.is_empty() {
return Err(GltfError::CircularChildren(format!(
"{:?}",
unprocessed_nodes
.iter()
.map(|(k, _v)| *k)
.collect::<Vec<_>>(),
)));
}

nodes.reverse();
Ok(Self {
nodes: nodes.into_iter().collect(),
})
}
}

impl<'a> Iterator for GltfTreeIterator<'a> {
type Item = Node<'a>;

fn next(&mut self) -> Option<Self::Item> {
self.nodes.pop()
}
}

impl<'a> ExactSizeIterator for GltfTreeIterator<'a> {
fn len(&self) -> usize {
self.nodes.len()
}
}

enum ImageOrPath {
Image {
image: Image,
Expand Down Expand Up @@ -2415,6 +2331,51 @@ fn material_needs_tangents(material: &Material) -> bool {
false
}

/// Checks all glTF nodes for cycles, starting at the scene root.
#[expect(
clippy::result_large_err,
reason = "need to be signature compatible with `load_gltf`"
)]
fn check_gltf_for_cycles(gltf: &gltf::Gltf) -> Result<(), GltfError> {
// Initialize with the scene roots.
let mut roots = FixedBitSet::with_capacity(gltf.nodes().len());
for root in gltf.scenes().flat_map(|scene| scene.nodes()) {
roots.insert(root.index());
}

// Check each one.
let mut visited = FixedBitSet::with_capacity(gltf.nodes().len());
for root in roots.ones() {
check(gltf.nodes().nth(root).unwrap(), &mut visited)?;
}
return Ok(());

// Depth first search.
#[expect(
clippy::result_large_err,
reason = "need to be signature compatible with `load_gltf`"
)]
fn check(node: Node, visited: &mut FixedBitSet) -> Result<(), GltfError> {
// Do we have a cycle?
if visited.contains(node.index()) {
return Err(GltfError::CircularChildren(format!(
"glTF nodes form a cycle: {} -> {}",
visited.ones().map(|bit| bit.to_string()).join(" -> "),
node.index()
)));
}

// Recurse.
visited.insert(node.index());
for kid in node.children() {
check(kid, visited)?;
}
visited.remove(node.index());

Ok(())
}
}

#[cfg(test)]
mod test {
use std::path::Path;
Expand Down