Dynamic addition of particles

examples2d/src/dynamic_add.rs

@@ -0,0 +1,112 @@
+use wgsparkl2d::rapier::prelude::{ColliderBuilder, RigidBodyBuilder};
+use wgsparkl_testbed2d::{wgsparkl, Callbacks, RapierData};
+
+use bevy::render::renderer::RenderDevice;
+use nalgebra::{vector, Vector2};
+use wgsparkl::models::DruckerPrager;
+use wgsparkl::{
+    models::ElasticCoefficients,
+    pipeline::MpmData,
+    solver::{Particle, SimulationParams},
+};
+use wgsparkl2d::solver::ParticleDynamics;
+use wgsparkl_testbed2d::{AppState, PhysicsContext};
+
+pub fn dynamic_demo(
+    device: RenderDevice,
+    app_state: &mut AppState,
+    callbacks: &mut Callbacks,
+) -> PhysicsContext {
+    let mut rapier_data = RapierData::default();
+    let device = device.wgpu_device();
+
+    let offset_y = 46.0;
+    let cell_width = 0.2;
+    let mut particles = vec![];
+    let position =
+        vector![-20f32, 0.0] + vector![0.5, 0.5] * cell_width / 2.0 + Vector2::y() * offset_y;
+    let density = 1000.0;
+    let radius = cell_width / 4f32;
+    let particle_proto = Particle {
+        position,
+        dynamics: ParticleDynamics::with_density(radius, density),
+        model: ElasticCoefficients::from_young_modulus(10_000_000.0, 0.2),
+        plasticity: Some(DruckerPrager::new(10_000_000.0, 0.2)),
+        phase: None,
+        color: None,
+    };
+    particles.push(particle_proto);
+
+    if !app_state.restarting {
+        app_state.num_substeps = 10;
+        app_state.gravity_factor = 1.0;
+    };
+
+    let params = SimulationParams {
+        gravity: vector![0.0, -9.81] * app_state.gravity_factor,
+        dt: (1.0 / 60.0) / (app_state.num_substeps as f32),
+        padding: 0.0,
+    };
+
+    /*
+     * Static platforms.
+     */
+    let rb = RigidBodyBuilder::fixed().translation(vector![35.0, -1.0]);
+    let rb_handle = rapier_data.bodies.insert(rb);
+    let co = ColliderBuilder::cuboid(42.0, 1.0);
+    rapier_data
+        .colliders
+        .insert_with_parent(co, rb_handle, &mut rapier_data.bodies);
+
+    let rb = RigidBodyBuilder::fixed()
+        .translation(vector![-25.0, 45.0])
+        .rotation(0.5);
+    let rb_handle = rapier_data.bodies.insert(rb);
+    let co = ColliderBuilder::cuboid(1.0, 52.0);
+    rapier_data
+        .colliders
+        .insert_with_parent(co, rb_handle, &mut rapier_data.bodies);
+
+    let rb = RigidBodyBuilder::fixed()
+        .translation(vector![95.0, 45.0])
+        .rotation(-0.5);
+    let rb_handle = rapier_data.bodies.insert(rb);
+    let co = ColliderBuilder::cuboid(1.0, 52.0);
+    rapier_data
+        .colliders
+        .insert_with_parent(co, rb_handle, &mut rapier_data.bodies);
+
+    let mut tick = 0;
+    callbacks.0.push(Box::new(
+        move |_, physics: &mut PhysicsContext, _, _, queue| {
+            tick += 1;
+            if tick % 2 != 0 {
+                // Do not add particles each frame, to avoid clumping particles together.
+                return;
+            }
+            for i in 0..500 {
+                let mut particle = particle_proto.clone();
+                particle.position += vector![1.0, 0.0] * (i as f32) * cell_width * 1.1;
+                physics.push_particle(queue, &particle);
+            }
+            physics.reset_graphics = true;
+        },
+    ));
+
+    let data = MpmData::new(
+        device,
+        params,
+        &particles,
+        100_000,
+        &rapier_data.bodies,
+        &rapier_data.colliders,
+        cell_width,
+        60_000,
+    );
+    PhysicsContext {
+        data,
+        rapier_data,
+        particles,
+        reset_graphics: false,
+    }
+}

examples2d/src/elastic_cut2.rs

@@ -103,6 +103,7 @@ pub fn elastic_cut_demo(
         device,
         params,
         &particles,
+        particles.len(),
         &rapier_data.bodies,
         &rapier_data.colliders,
         cell_width,
@@ -112,5 +113,6 @@ pub fn elastic_cut_demo(
         data,
         rapier_data,
         particles,
+        reset_graphics: false,
     }
 }

examples2d/src/elasticity2.rs

@@ -85,6 +85,7 @@ pub fn elastic_demo(
         device,
         params,
         &particles,
+        particles.len(),
         &rapier_data.bodies,
         &rapier_data.colliders,
         cell_width,
@@ -94,5 +95,6 @@ pub fn elastic_demo(
         data,
         rapier_data,
         particles,
+        reset_graphics: false,
     }
 }

examples2d/src/main.rs

@@ -1,6 +1,7 @@
 use bevy::prelude::*;
 use wgsparkl_testbed2d::{init_testbed, SceneInitFn, SceneInits};
 
+mod dynamic_add;
 mod elastic_cut2;
 mod elasticity2;
 mod sand2;
@@ -20,6 +21,10 @@ pub fn main() {
 fn register_scenes(world: &mut World) {
     let scenes: Vec<(String, SceneInitFn)> = vec![
         ("sand".to_string(), Box::new(sand2::sand_demo)),
+        (
+            "dynamic add".to_string(),
+            Box::new(dynamic_add::dynamic_demo),
+        ),
         ("elastic".to_string(), Box::new(elasticity2::elastic_demo)),
         (
             "elastic cut".to_string(),

examples2d/src/sand2.rs

@@ -163,6 +163,7 @@ pub fn sand_demo(
         device,
         params,
         &particles,
+        particles.len(),
         &rapier_data.bodies,
         &rapier_data.colliders,
         cell_width,
@@ -172,5 +173,6 @@ pub fn sand_demo(
         data,
         rapier_data,
         particles,
+        reset_graphics: false,
     }
 }

examples3d/src/banana3.rs

@@ -114,6 +114,7 @@ pub fn demo(
         device.wgpu_device(),
         params,
         &particles,
+        particles.len(),
         &rapier_data.bodies,
         &rapier_data.colliders,
         1f32 / default_scene::SAMPLE_PER_UNIT,
@@ -134,7 +135,7 @@ pub fn demo(
 fn move_knife_function(body_handle: RigidBodyHandle) -> Callback {
     let mut ticks = 0;
     Box::new(
-        move |_render, physics: &mut PhysicsContext, _timestamps, _app_state: &AppState| {
+        move |_render, physics: &mut PhysicsContext, _timestamps, _app_state: &AppState, _| {
             let t = ticks as f32 * physics.rapier_data.integration_parameters.dt;
             ticks += 1;
 

examples3d/src/dynamic_add.rs

@@ -0,0 +1,69 @@
+use wgsparkl_testbed3d::{wgsparkl, Callbacks, RapierData};
+
+use bevy::render::renderer::RenderDevice;
+use nalgebra::vector;
+use wgsparkl::models::DruckerPrager;
+use wgsparkl::{
+    models::ElasticCoefficients,
+    pipeline::MpmData,
+    solver::{Particle, ParticleDynamics, SimulationParams},
+};
+use wgsparkl_testbed3d::{AppState, PhysicsContext};
+
+use crate::utils::default_scene;
+
+pub fn dynamic_demo(
+    device: RenderDevice,
+    app_state: &mut AppState,
+    callbacks: &mut Callbacks,
+) -> PhysicsContext {
+    let mut rapier_data = RapierData::default();
+    let device = device.wgpu_device();
+
+    if !app_state.restarting {
+        app_state.num_substeps = 20;
+        app_state.gravity_factor = 1.0;
+    };
+
+    let params = SimulationParams {
+        gravity: vector![0.0, -9.81, 0.0] * app_state.gravity_factor,
+        dt: (1.0 / 60.0) / (app_state.num_substeps as f32),
+    };
+
+    default_scene::spawn_ground_and_walls(&mut rapier_data);
+    let cell_width = 1.0;
+
+    let position = vector![0.0, 10f32, 0.0];
+    callbacks.0.push(Box::new(
+        move |_, physics: &mut PhysicsContext, _, _, queue| {
+            physics.data.particles.push(
+                queue,
+                &Particle {
+                    position,
+                    dynamics: ParticleDynamics::with_density(cell_width / 4.0, 2700.0),
+                    model: ElasticCoefficients::from_young_modulus(2_000_000_000.0, 0.2),
+                    plasticity: Some(DruckerPrager::new(2_000_000_000.0, 0.2)),
+                    phase: None,
+                    color: None,
+                },
+            )
+        },
+    ));
+
+    let particles = vec![];
+    let data = MpmData::new(
+        device,
+        params,
+        &particles,
+        1_000,
+        &rapier_data.bodies,
+        &rapier_data.colliders,
+        cell_width,
+        60_000,
+    );
+    PhysicsContext {
+        data,
+        rapier_data,
+        particles,
+    }
+}

examples3d/src/elastic_cut3.rs

@@ -87,6 +87,7 @@ pub fn elastic_cut_demo(
         device,
         params,
         &particles,
+        particles.len(),
         &rapier_data.bodies,
         &rapier_data.colliders,
         cell_width,

examples3d/src/glb_to_point_cloud_color.rs

@@ -53,6 +53,7 @@ pub fn elastic_color_model_demo(
         device.wgpu_device(),
         params,
         &particles,
+        particles.len(),
         &rapier_data.bodies,
         &rapier_data.colliders,
         1f32 / default_scene::SAMPLE_PER_UNIT,

examples3d/src/heightfield3.rs

@@ -72,6 +72,7 @@ pub fn heightfield_demo(
         device,
         params,
         &particles,
+        particles.len(),
         &rapier_data.bodies,
         &rapier_data.colliders,
         cell_width,

examples3d/src/main.rs

@@ -4,6 +4,7 @@ use wgsparkl_testbed3d::{init_testbed, SceneInitFn, SceneInits};
 pub mod utils;
 
 mod banana3;
+mod dynamic_add;
 mod elastic_cut3;
 mod glb_to_point_cloud_color;
 mod heightfield3;
@@ -24,6 +25,10 @@ pub fn main() {
 fn register_scenes(world: &mut World) {
     let scenes: Vec<(String, SceneInitFn)> = vec![
         ("sand".to_string(), Box::new(sand3::sand_demo)),
+        (
+            "dynamic addition".to_string(),
+            Box::new(dynamic_add::dynamic_demo),
+        ),
         (
             "heightfield".to_string(),
             Box::new(heightfield3::heightfield_demo),

examples3d/src/sand3.rs

@@ -88,6 +88,7 @@ pub fn sand_demo(
         device,
         params,
         &particles,
+        particles.len(),
         &rapier_data.bodies,
         &rapier_data.colliders,
         cell_width,

src/grid/grid.rs

@@ -69,8 +69,14 @@ impl WgGrid {
                         (grid.debug.buffer(), 8),
                     ],
                 )
-                .bind(1, [particles.positions.buffer()])
-                .queue((particles.len() as u32).div_ceil(GRID_WORKGROUP_SIZE));
+                .bind(
+                    1,
+                    [
+                        particles.current_size.buffer(),
+                        particles.positions.buffer(),
+                    ],
+                )
+                .queue(particles.current_size_cached.div_ceil(GRID_WORKGROUP_SIZE));
 
             // Ensure blocks exist wherever we have rigid particles that might affect
             // other blocks. This is done in two passes:
@@ -113,7 +119,6 @@ impl WgGrid {
                 )
                 .queue((rigid_particles.len() as u32).div_ceil(GRID_WORKGROUP_SIZE));
 
-            // TODO: handle grid buffer resizing
             sparse_grid_has_the_correct_size = true;
         }
 
@@ -149,15 +154,21 @@ impl WgGrid {
                     grid.active_blocks.buffer(),
                 ],
             )
-            .bind(1, [particles.positions.buffer()])
+            .bind(
+                1,
+                [
+                    particles.current_size.buffer(),
+                    particles.positions.buffer(),
+                ],
+            )
             .queue(n_groups);
 
         KernelInvocationBuilder::new(queue, &sort_module.copy_particles_len_to_scan_value)
             .bind_at(
                 0,
                 [(grid.meta.buffer(), 0), (grid.active_blocks.buffer(), 2)],
             )
-            .bind_at(1, [(grid.scan_values.buffer(), 1)])
+            .bind_at(1, [(grid.scan_values.buffer(), 2)])
             .queue_indirect(n_block_groups.clone());
 
         prefix_sum_module.queue(queue, prefix_sum, &grid.scan_values);
@@ -167,7 +178,7 @@ impl WgGrid {
                 0,
                 [(grid.meta.buffer(), 0), (grid.active_blocks.buffer(), 2)],
             )
-            .bind_at(1, [(grid.scan_values.buffer(), 1)])
+            .bind_at(1, [(grid.scan_values.buffer(), 2)])
             .queue_indirect(n_block_groups.clone());
 
         // Reset here so the linked list heads get reset before `finalize_particles_sort` which
@@ -196,6 +207,7 @@ impl WgGrid {
             .bind(
                 1,
                 [
+                    particles.current_size.buffer(),
                     particles.positions.buffer(),
                     grid.scan_values.buffer(),
                     particles.sorted_ids.buffer(),
@@ -370,7 +382,8 @@ mod test {
             }
         }
 
-        let particles = GpuParticles::from_particles(gpu.device(), &cpu_particles);
+        let particles =
+            GpuParticles::from_particles(gpu.device(), &cpu_particles, cpu_particles.len());
         let grid = GpuGrid::with_capacity(gpu.device(), 100_000, cell_width);
         let mut prefix_sum = PrefixSumWorkspace::with_capacity(gpu.device(), 100_000);
         let mut queue = KernelInvocationQueue::new(gpu.device());