Add transform hierarchy stress test (#4170)

## Objective

There recently was a discussion on Discord about a possible test case for stress-testing transform hierarchies.

## Solution

Create a test case for stress testing transform propagation.

*Edit:* I have scrapped my previous example and built something more functional and less focused on visuals.

There are three test setups:

- `TestCase::Tree` recursively creates a tree with a specified depth and branch width
- `TestCase::NonUniformTree` is the same as `Tree` but omits nodes in a way that makes the tree "lean" towards one side, like this:
  <details>
  <summary></summary>

  ![image](https://user-images.githubusercontent.com/3957610/158069737-2ddf4e4a-7d5c-4ee5-8566-424a54a06723.png)
  </details>
- `TestCase::Humanoids` creates one or more separate hierarchies based on the structure of common humanoid rigs
  - this can both insert `active` and `inactive` instances of the human rig

It's possible to parameterize which parts of the hierarchy get updated (transform change) and which remain unchanged. This is based on @james7132 suggestion:
There's a probability to decide which entities should remain static. On top of that these changes can be limited to a certain range in the hierarchy (min_depth..max_depth).
This commit is contained in:
Alex 2022-03-21 20:36:46 +00:00
parent fa791d6bb8
commit 54fbaf4b4c
3 changed files with 567 additions and 0 deletions

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@ -592,3 +592,9 @@ icon = "@mipmap/ic_launcher"
build_targets = ["aarch64-linux-android", "armv7-linux-androideabi"]
min_sdk_version = 16
target_sdk_version = 29
# Stress Tests
[[example]]
name = "transform_hierarchy"
path = "examples/stress_tests/transform_hierarchy.rs"

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@ -66,6 +66,7 @@ git checkout v0.4.0
- [WASM](#wasm)
- [Setup](#setup-2)
- [Build & Run](#build--run-2)
- [Stress Tests](#stress-tests)
# The Bare Minimum
@ -420,3 +421,17 @@ ruby -run -ehttpd examples/wasm
To load assets, they need to be available in the folder examples/wasm/assets. Cloning this
repository will set it up as a symlink on Linux and macOS, but you will need to manually move
the assets on Windows.
# Stress Tests
These examples are used to test the performance and stability of various parts of the engine in an isolated way.
Due to the focus on performance it's recommended to run the stress tests in release mode:
```sh
cargo run --release --example <example name>
```
Example | File | Description
--- | --- | ---
`transform_hierarchy.rs` | [`stress_tests/transform_hierarchy.rs`](./stress_tests/transform_hierarchy.rs) | Various test cases for hierarchy and transform propagation performance

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@ -0,0 +1,546 @@
//! Hierarchy and transform propagation stress test.
//!
//! Running this example:
//!
//! ```
//! cargo r --release --example transform_hierarchy -- <configuration name>
//! ```
//!
//! | Configuration | Description |
//! | -------------------- | ----------------------------------------------------------------- |
//! | `large_tree` | A fairly wide and deep tree. |
//! | `wide_tree` | A shallow but very wide tree. |
//! | `deep_tree` | A deep but not very wide tree. |
//! | `chain` | A chain. 2500 levels deep. |
//! | `update_leaves` | Same as `large_tree`, but only leaves are updated. |
//! | `update_shallow` | Same as `large_tree`, but only the first few levels are updated. |
//! | `humanoids_active` | 4000 active humanoid rigs. |
//! | `humanoids_inactive` | 4000 humanoid rigs. Only 10 are active. |
//! | `humanoids_mixed` | 2000 active and 2000 inactive humanoid rigs. |
use bevy::prelude::*;
use rand::Rng;
/// pre-defined test configurations with name
const CONFIGS: [(&str, Cfg); 9] = [
(
"large_tree",
Cfg {
test_case: TestCase::NonUniformTree {
depth: 18,
branch_width: 8,
},
update_filter: UpdateFilter {
probability: 0.5,
min_depth: 0,
max_depth: u32::MAX,
},
},
),
(
"wide_tree",
Cfg {
test_case: TestCase::Tree {
depth: 3,
branch_width: 500,
},
update_filter: UpdateFilter {
probability: 0.5,
min_depth: 0,
max_depth: u32::MAX,
},
},
),
(
"deep_tree",
Cfg {
test_case: TestCase::NonUniformTree {
depth: 25,
branch_width: 2,
},
update_filter: UpdateFilter {
probability: 0.5,
min_depth: 0,
max_depth: u32::MAX,
},
},
),
(
"chain",
Cfg {
test_case: TestCase::Tree {
depth: 2500,
branch_width: 1,
},
update_filter: UpdateFilter {
probability: 0.5,
min_depth: 0,
max_depth: u32::MAX,
},
},
),
(
"update_leaves",
Cfg {
test_case: TestCase::Tree {
depth: 18,
branch_width: 2,
},
update_filter: UpdateFilter {
probability: 0.5,
min_depth: 17,
max_depth: u32::MAX,
},
},
),
(
"update_shallow",
Cfg {
test_case: TestCase::Tree {
depth: 18,
branch_width: 2,
},
update_filter: UpdateFilter {
probability: 0.5,
min_depth: 0,
max_depth: 8,
},
},
),
(
"humanoids_active",
Cfg {
test_case: TestCase::Humanoids {
active: 4000,
inactive: 0,
},
update_filter: UpdateFilter {
probability: 1.0,
min_depth: 0,
max_depth: u32::MAX,
},
},
),
(
"humanoids_inactive",
Cfg {
test_case: TestCase::Humanoids {
active: 10,
inactive: 3990,
},
update_filter: UpdateFilter {
probability: 1.0,
min_depth: 0,
max_depth: u32::MAX,
},
},
),
(
"humanoids_mixed",
Cfg {
test_case: TestCase::Humanoids {
active: 2000,
inactive: 2000,
},
update_filter: UpdateFilter {
probability: 1.0,
min_depth: 0,
max_depth: u32::MAX,
},
},
),
];
fn print_available_configs() {
println!("available configurations:");
for (name, _) in CONFIGS {
println!(" {name}");
}
}
fn main() {
// parse cli argument and find the selected test configuration
let cfg: Cfg = match std::env::args().nth(1) {
Some(arg) => match CONFIGS.iter().find(|(name, _)| *name == arg) {
Some((name, cfg)) => {
println!("test configuration: {name}");
cfg.clone()
}
None => {
println!("test configuration \"{arg}\" not found.\n");
print_available_configs();
return;
}
},
None => {
println!("missing argument: <test configuration>\n");
print_available_configs();
return;
}
};
println!("\n{:#?}", cfg);
App::new()
.insert_resource(cfg)
.add_plugins(MinimalPlugins)
.add_plugin(TransformPlugin::default())
.add_startup_system(setup)
.add_system(update)
.run()
}
/// test configuration
#[derive(Debug, Clone)]
struct Cfg {
/// which test case should be inserted
test_case: TestCase,
/// which entities should be updated
update_filter: UpdateFilter,
}
#[allow(unused)]
#[derive(Debug, Clone)]
enum TestCase {
/// a uniform tree, exponentially growing with depth
Tree {
/// total depth
depth: u32,
/// number of children per node
branch_width: u32,
},
/// a non uniform tree (one side is deeper than the other)
/// creates significantly less nodes than `TestCase::Tree` with the same parameters
NonUniformTree {
/// the maximum depth
depth: u32,
/// max number of children per node
branch_width: u32,
},
/// one or multiple humanoid rigs
Humanoids {
/// number of active instances (uses the specified [`UpdateFilter`])
active: u32,
/// number of inactive instances (always inactive)
inactive: u32,
},
}
/// a filter to restrict which nodes are updated
#[derive(Debug, Clone)]
struct UpdateFilter {
/// starting depth (inclusive)
min_depth: u32,
/// end depth (inclusive)
max_depth: u32,
/// probability of a node to get updated (evaluated at insertion time, not during update)
/// 0 (never) .. 1 (always)
probability: f32,
}
/// update component with some per-component value
#[derive(Component)]
struct Update(f32);
/// update positions system
fn update(time: Res<Time>, mut query: Query<(&mut Transform, &mut Update)>) {
for (mut t, mut u) in query.iter_mut() {
u.0 += time.delta_seconds() * 0.1;
set_translation(&mut t.translation, u.0);
}
}
/// set translation based on the angle `a`
fn set_translation(translation: &mut Vec3, a: f32) {
translation.x = a.cos() * 32.0;
translation.y = a.sin() * 32.0;
}
fn setup(mut commands: Commands, cfg: Res<Cfg>) {
let mut cam = OrthographicCameraBundle::new_2d();
cam.transform.translation.z = 100.0;
commands.spawn_bundle(cam);
let result = match cfg.test_case {
TestCase::Tree {
depth,
branch_width,
} => {
let tree = gen_tree(depth, branch_width);
spawn_tree(&tree, &mut commands, &cfg.update_filter, default())
}
TestCase::NonUniformTree {
depth,
branch_width,
} => {
let tree = gen_non_uniform_tree(depth, branch_width);
spawn_tree(&tree, &mut commands, &cfg.update_filter, default())
}
TestCase::Humanoids { active, inactive } => {
let mut result = InsertResult::default();
let mut rng = rand::thread_rng();
for _ in 0..active {
result.combine(spawn_tree(
&HUMANOID_RIG,
&mut commands,
&cfg.update_filter,
Transform::from_xyz(
rng.gen::<f32>() * 500.0 - 250.0,
rng.gen::<f32>() * 500.0 - 250.0,
0.0,
),
));
}
for _ in 0..inactive {
result.combine(spawn_tree(
&HUMANOID_RIG,
&mut commands,
&UpdateFilter {
// force inactive by setting the probability < 0
probability: -1.0,
..cfg.update_filter
},
Transform::from_xyz(
rng.gen::<f32>() * 500.0 - 250.0,
rng.gen::<f32>() * 500.0 - 250.0,
0.0,
),
));
}
result
}
};
println!("\n{:#?}", result);
}
/// overview of the inserted hierarchy
#[derive(Default, Debug)]
struct InsertResult {
/// total number of nodes inserted
inserted_nodes: usize,
/// number of nodes that get updated each frame
active_nodes: usize,
/// maximum depth of the hierarchy tree
maximum_depth: usize,
}
impl InsertResult {
fn combine(&mut self, rhs: Self) -> &mut Self {
self.inserted_nodes += rhs.inserted_nodes;
self.active_nodes += rhs.active_nodes;
self.maximum_depth = self.maximum_depth.max(rhs.maximum_depth);
self
}
}
/// spawns a tree defined by a parent map (excluding root)
/// the parent map must be ordered (parent must exist before child)
fn spawn_tree(
parent_map: &[usize],
commands: &mut Commands,
update_filter: &UpdateFilter,
root_transform: Transform,
) -> InsertResult {
// total count (# of nodes + root)
let count = parent_map.len() + 1;
#[derive(Default, Clone, Copy)]
struct NodeInfo {
child_count: u32,
depth: u32,
}
// node index -> entity lookup list
let mut ents: Vec<Entity> = Vec::with_capacity(count);
let mut node_info: Vec<NodeInfo> = vec![default(); count];
for (i, &parent_idx) in parent_map.iter().enumerate() {
// assert spawn order (parent must be processed before child)
assert!(parent_idx <= i, "invalid spawn order");
node_info[parent_idx].child_count += 1;
}
// insert root
ents.push(
commands
.spawn()
.insert(root_transform)
.insert(GlobalTransform::default())
.id(),
);
let mut result = InsertResult::default();
let mut rng = rand::thread_rng();
// used to count through the number of children (used only for visual layout)
let mut child_idx: Vec<u16> = vec![0; count];
// insert children
for (current_idx, &parent_idx) in parent_map.iter().enumerate() {
let current_idx = current_idx + 1;
// separation factor to visually separate children (0..1)
let sep = child_idx[parent_idx] as f32 / node_info[parent_idx].child_count as f32;
child_idx[parent_idx] += 1;
// calculate and set depth
// this works because it's guaranteed that we have already iterated over the parent
let depth = node_info[parent_idx].depth + 1;
let info = &mut node_info[current_idx];
info.depth = depth;
// update max depth of tree
result.maximum_depth = result.maximum_depth.max(depth.try_into().unwrap());
// insert child
let child_entity = {
let mut cmd = commands.spawn();
// check whether or not to update this node
let update = (rng.gen::<f32>() <= update_filter.probability)
&& (depth >= update_filter.min_depth && depth <= update_filter.max_depth);
if update {
cmd.insert(Update(sep));
result.active_nodes += 1;
}
let transform = {
let mut translation = Vec3::ZERO;
// use the same placement fn as the `update` system
// this way the entities won't be all at (0, 0, 0) when they don't have an `Update` component
set_translation(&mut translation, sep);
Transform::from_translation(translation)
};
// only insert the components necessary for the transform propagation
cmd.insert(transform).insert(GlobalTransform::default());
cmd.id()
};
commands
.get_or_spawn(ents[parent_idx])
.add_child(child_entity);
ents.push(child_entity);
}
result.inserted_nodes = ents.len();
result
}
/// generate a tree `depth` levels deep, where each node has `branch_width` children
fn gen_tree(depth: u32, branch_width: u32) -> Vec<usize> {
// calculate the total count of branches
let mut count: usize = 0;
for i in 0..(depth - 1) {
count += TryInto::<usize>::try_into(branch_width.pow(i)).unwrap();
}
// the tree is built using this pattern:
// 0, 0, 0, ... 1, 1, 1, ... 2, 2, 2, ... (count - 1)
(0..count)
.flat_map(|i| std::iter::repeat(i).take(branch_width.try_into().unwrap()))
.collect()
}
/// recursive part of [`gen_non_uniform_tree`]
fn add_children_non_uniform(
tree: &mut Vec<usize>,
parent: usize,
mut curr_depth: u32,
max_branch_width: u32,
) {
for _ in 0..max_branch_width {
tree.push(parent);
curr_depth = curr_depth.checked_sub(1).unwrap();
if curr_depth == 0 {
return;
}
add_children_non_uniform(tree, tree.len(), curr_depth, max_branch_width);
}
}
/// generate a tree that has more nodes on one side that the other
/// the deepest hierarchy path is `max_depth` and the widest branches have `max_branch_width` children
fn gen_non_uniform_tree(max_depth: u32, max_branch_width: u32) -> Vec<usize> {
let mut tree = Vec::new();
add_children_non_uniform(&mut tree, 0, max_depth, max_branch_width);
tree
}
/// parent map for a decently complex humanoid rig (based on mixamo rig)
const HUMANOID_RIG: [usize; 67] = [
// (0: root)
0, // 1: hips
1, // 2: spine
2, // 3: spine 1
3, // 4: spine 2
4, // 5: neck
5, // 6: head
6, // 7: head top
6, // 8: left eye
6, // 9: right eye
4, // 10: left shoulder
10, // 11: left arm
11, // 12: left forearm
12, // 13: left hand
13, // 14: left hand thumb 1
14, // 15: left hand thumb 2
15, // 16: left hand thumb 3
16, // 17: left hand thumb 4
13, // 18: left hand index 1
18, // 19: left hand index 2
19, // 20: left hand index 3
20, // 21: left hand index 4
13, // 22: left hand middle 1
22, // 23: left hand middle 2
23, // 24: left hand middle 3
24, // 25: left hand middle 4
13, // 26: left hand ring 1
26, // 27: left hand ring 2
27, // 28: left hand ring 3
28, // 29: left hand ring 4
13, // 30: left hand pinky 1
30, // 31: left hand pinky 2
31, // 32: left hand pinky 3
32, // 33: left hand pinky 4
4, // 34: right shoulder
34, // 35: right arm
35, // 36: right forearm
36, // 37: right hand
37, // 38: right hand thumb 1
38, // 39: right hand thumb 2
39, // 40: right hand thumb 3
40, // 41: right hand thumb 4
37, // 42: right hand index 1
42, // 43: right hand index 2
43, // 44: right hand index 3
44, // 45: right hand index 4
37, // 46: right hand middle 1
46, // 47: right hand middle 2
47, // 48: right hand middle 3
48, // 49: right hand middle 4
37, // 50: right hand ring 1
50, // 51: right hand ring 2
51, // 52: right hand ring 3
52, // 53: right hand ring 4
37, // 54: right hand pinky 1
54, // 55: right hand pinky 2
55, // 56: right hand pinky 3
56, // 57: right hand pinky 4
1, // 58: left upper leg
58, // 59: left leg
59, // 60: left foot
60, // 61: left toe base
61, // 62: left toe end
1, // 63: right upper leg
63, // 64: right leg
64, // 65: right foot
65, // 66: right toe base
66, // 67: right toe end
];