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Optimize edge collision checking by sorting so they always follow in pairs

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Fix suspension constraint force being weird
This commit is contained in:
sergeypdev 2025-07-27 15:33:00 +04:00
parent 56f1eb1d15
commit 44a401344f
5 changed files with 102 additions and 43 deletions
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3
game/assets/assets.odin
View File

@ -565,8 +565,6 @@ assetman_fetch_or_load_internal :: proc(
modtime: physfs.sint64,
result: Asset_Cache_Result,
) {
tracy.Zone()
existing, has_existing := assetman.assets[key]
if has_existing {
@ -636,7 +634,6 @@ assetman_fetch_or_load :: proc(
modtime: physfs.sint64,
result: Asset_Cache_Result,
) {
tracy.Zone()
value, modtime, result = assetman_fetch_or_load_internal(
assetman,
key,

3
game/assets/parsers.odin
View File

@ -338,7 +338,6 @@ parse_convex :: proc(bytes: []byte, allocator := context.allocator) -> (Loaded_C
final_edges := make([]halfedge.Half_Edge, len(edges), allocator)
final_faces := make([]halfedge.Face, len(faces), allocator)
copy(final_vertices, vertices[:])
copy(final_edges, edges[:])
copy(final_faces, faces[:])
mesh := halfedge.Half_Edge_Mesh {
@ -349,6 +348,8 @@ parse_convex :: proc(bytes: []byte, allocator := context.allocator) -> (Loaded_C
extent = extent,
}
halfedge.sort_edges(mesh, edges[:])
// Center of mass calculation
total_volume := f32(0.0)
{

46
game/halfedge/halfedge.odin
View File

@ -51,11 +51,10 @@ mesh_from_vertex_index_list :: proc(
mesh: Half_Edge_Mesh
verts := make([]Vertex, len(vertices), allocator)
faces := make([]Face, num_faces, allocator)
edges := make([]Half_Edge, len(indices), allocator)
edges := make([]Half_Edge, len(indices), context.temp_allocator)
mesh.vertices = verts
mesh.faces = faces
mesh.edges = edges
min_pos, max_pos: Vec3 = max(f32), min(f32)
@ -128,9 +127,52 @@ mesh_from_vertex_index_list :: proc(
}
}
mesh.edges = make([]Half_Edge, len(edges), allocator)
sort_edges(mesh, edges)
return mesh
}
sort_edges :: proc(dst_mesh: Half_Edge_Mesh, unsorted_edges: []Half_Edge) {
assert(len(dst_mesh.edges) == len(unsorted_edges))
keys := make([]u32, len(unsorted_edges), context.temp_allocator)
for &e, i in unsorted_edges {
v0 := e.origin
v1 := unsorted_edges[e.next].origin
min_v := min(v0, v1)
max_v := max(v0, v1)
keys[i] = (u32(max_v) << 16) | u32(min_v)
}
sorted_edges_indices := slice.sort_with_indices(keys, context.temp_allocator)
unsorted_to_sorted_lookup := make([]Edge_Index, len(unsorted_edges), context.temp_allocator)
for i in 0 ..< len(unsorted_edges) {
unsorted_to_sorted_lookup[sorted_edges_indices[i]] = Edge_Index(i)
}
for i in 0 ..< len(unsorted_edges) {
sorted := &dst_mesh.edges[i]
sorted^ = unsorted_edges[sorted_edges_indices[i]]
sorted.twin = unsorted_to_sorted_lookup[sorted.twin]
sorted.next = unsorted_to_sorted_lookup[sorted.next]
sorted.prev = unsorted_to_sorted_lookup[sorted.prev]
}
for &v in dst_mesh.vertices {
v.edge = unsorted_to_sorted_lookup[v.edge]
}
for &f in dst_mesh.faces {
f.edge = unsorted_to_sorted_lookup[f.edge]
}
}
get_edge_points :: #force_inline proc(
mesh: Half_Edge_Mesh,
edge: Half_Edge,

38
game/physics/collision/convex.odin
View File

@ -1,7 +1,6 @@
package collision
import "base:runtime"
import "core:container/bit_array"
import "core:log"
import "core:math"
import lg "core:math/linalg"
@ -274,29 +273,34 @@ query_separation_edges :: proc(
runtime.DEFAULT_TEMP_ALLOCATOR_TEMP_GUARD()
checked_pairs: bit_array.Bit_Array
bit_array.init(&checked_pairs, len(a.edges) * len(b.edges), 0, context.temp_allocator)
a_len := len(a.edges)
// checked_pairs: bit_array.Bit_Array
// bit_array.init(&checked_pairs, len(a.edges) * len(b.edges), 0, context.temp_allocator)
// a_len := len(a.edges)
calc_pair_index :: #force_inline proc(a, b, a_len: int) -> int {
return (b * a_len) + a
}
for edge_a, edge_a_idx in a.edges {
for edge_b, edge_b_idx in b.edges {
pair_idx := calc_pair_index(edge_a_idx, edge_b_idx, a_len)
if bit_array.get(&checked_pairs, pair_idx) {
continue
}
assert(len(a.edges) % 2 == 0)
assert(len(b.edges) % 2 == 0)
for edge_a_idx := 0; edge_a_idx < len(a.edges); edge_a_idx += 2 {
edge_a := a.edges[edge_a_idx]
for edge_b_idx := 0; edge_b_idx < len(b.edges); edge_b_idx += 2 {
edge_b := b.edges[edge_b_idx]
// pair_idx := calc_pair_index(edge_a_idx, edge_b_idx, a_len)
// if bit_array.get(&checked_pairs, pair_idx) {
// continue
// }
// TODO: sort edges so twins are next to each other, then can just iterate with step = 2 and skip this bitfield
bit_array.set(&checked_pairs, pair_idx)
bit_array.set(&checked_pairs, calc_pair_index(int(edge_a.twin), edge_b_idx, a_len))
bit_array.set(&checked_pairs, calc_pair_index(edge_a_idx, int(edge_b.twin), a_len))
bit_array.set(
&checked_pairs,
calc_pair_index(int(edge_a.twin), int(edge_b.twin), a_len),
)
// bit_array.set(&checked_pairs, pair_idx)
// bit_array.set(&checked_pairs, calc_pair_index(int(edge_a.twin), edge_b_idx, a_len))
// bit_array.set(&checked_pairs, calc_pair_index(edge_a_idx, int(edge_b.twin), a_len))
// bit_array.set(
// &checked_pairs,
// calc_pair_index(int(edge_a.twin), int(edge_b.twin), a_len),
// )
if build_minkowski_face(a, b, edge_a, edge_b) {
edge_a1, edge_a2 := halfedge.get_edge_points(a, edge_a)

55
game/physics/simulation.odin
View File

@ -148,7 +148,7 @@ build_dynamic_tlas :: proc(
phys_aabb := body_get_aabb(body)
EXPAND_K :: 2
EXPAND_K :: 10
expand := lg.abs(EXPAND_K * config.timestep * body.v) + 0.1
phys_aabb.extent += expand * 0.5
@ -329,6 +329,9 @@ raycast :: proc(
normal = normal2
}
// TODO: raycast_level and raycast_bodies should return a normalized vec
normal = lg.normalize0(normal)
return
}
@ -472,6 +475,7 @@ find_new_contacts :: proc(
sim_cache: ^Sim_Cache,
static_tlas: ^Static_TLAS,
dyn_tlas: ^Dynamic_TLAS,
config: Solver_Config,
) {
tracy.Zone()
@ -503,6 +507,9 @@ find_new_contacts :: proc(
shape_a_aabb := shape_get_aabb(shape_a^)
shape_a_aabb = body_transform_shape_aabb(body, shape_a_aabb)
EXPAND_K :: 2
expand := lg.abs(EXPAND_K * config.timestep * body.v) + 0.1
shape_a_aabb.extent += expand * 0.5
shapes_b_it := shapes_iterator(sim_state, other_body.shape)
@ -598,16 +605,18 @@ find_new_contacts :: proc(
)
tri := get_triangle(vertices, indices, tri_idx)
prim_aabb := get_triangle_aabb(tri)
prim_aabb.min -= 0.1
prim_aabb.max += 0.1
if bvh.test_aabb_vs_aabb(
body_aabb_in_Level_geom_space,
prim_aabb,
) {
tracy.ZoneN("body_vs_level_geom")
// tracy.ZoneN("body_vs_triangle", false)
shapes_it := shapes_iterator(sim_state, body.shape)
for shape in shapes_iterator_next(&shapes_it) {
tracy.ZoneN("body_shape_vs_level_geom")
// tracy.ZoneN("body_shape_vs_triangle")
shape_idx := shapes_it.counter - 1
shape_aabb := shape_get_aabb(shape^)
@ -920,7 +929,7 @@ update_contacts :: proc(sim_state: ^Sim_State, sim_cache: ^Sim_Cache, static_tla
}
calculate_soft_constraint_params :: proc(
natural_freq, damping_ratio, dt: f32,
natural_freq, damping_ratio, dt: f64,
) -> (
bias_rate: f32,
mass_coef: f32,
@ -930,9 +939,9 @@ calculate_soft_constraint_params :: proc(
a1 := 2.0 * damping_ratio + omega * dt
a2 := dt * omega * a1
a3 := 1.0 / (1.0 + a2)
bias_rate = omega / a1
mass_coef = a2 * a3
impulse_coef = a3
bias_rate = f32(omega / a1)
mass_coef = f32(a2 * a3)
impulse_coef = f32(a3)
return
}
@ -944,7 +953,7 @@ pgs_solve_contacts :: proc(
inv_dt: f32,
apply_bias: bool,
) {
bias_rate, mass_coef, impulse_coef := calculate_soft_constraint_params(40, 1.0, dt)
bias_rate, mass_coef, impulse_coef := calculate_soft_constraint_params(30, 0.8, f64(dt))
if !apply_bias {
mass_coef = 1
bias_rate = 0
@ -1303,7 +1312,7 @@ pgs_solve_suspension :: proc(
forward := wheel_get_forward_vec(body, v)
right := wheel_get_right_vec(body, v)
w_normal := get_body_angular_inverse_mass(body, dir)
w_normal := get_body_angular_inverse_mass(body, -v.hit_normal)
inv_w_normal := 1.0 / w_normal
// Drive force
@ -1343,12 +1352,12 @@ pgs_solve_suspension :: proc(
// Spring force
{
bias_coef, mass_coef, impulse_coef := calculate_soft_constraint_params(
v.natural_frequency,
v.damping,
dt,
f64(v.natural_frequency),
f64(v.damping),
f64(dt),
)
vel := lg.dot(body_velocity_at_point(body, wheel_world_pos), dir)
vel := lg.dot(body_velocity_at_point(body, v.hit_point), -v.hit_normal)
x := v.hit_t
separation := v.rest - x
@ -1357,7 +1366,11 @@ pgs_solve_suspension :: proc(
impulse_coef * v.spring_impulse
v.spring_impulse += incremental_impulse
apply_velocity_correction(body, incremental_impulse * dir, wheel_world_pos)
apply_velocity_correction(
body,
incremental_impulse * v.hit_normal,
v.hit_point,
)
}
// Positive means spinning forward
@ -1584,11 +1597,7 @@ pgs_substep :: proc(
forward := wheel_get_forward_vec(body, s)
right := wheel_get_right_vec(body, s)
apply_velocity_correction(
body,
s.spring_impulse * body_local_to_world_vec(body, s.rel_dir),
p,
)
apply_velocity_correction(body, s.spring_impulse * -s.hit_normal, hit_p)
apply_velocity_correction(body, s.lateral_impulse * right, p)
apply_velocity_correction(body, s.longitudinal_impulse * forward, hit_p)
@ -1663,7 +1672,13 @@ simulate_step :: proc(
build_dynamic_tlas(sim_state, config, &sim_state.dynamic_tlas)
remove_invalid_contacts(sim_state, sim_cache, sim_state.static_tlas, sim_state.dynamic_tlas)
find_new_contacts(sim_state, sim_cache, &sim_state.static_tlas, &sim_state.dynamic_tlas)
find_new_contacts(
sim_state,
sim_cache,
&sim_state.static_tlas,
&sim_state.dynamic_tlas,
config,
)
update_contacts(sim_state, sim_cache, &sim_state.static_tlas)
Solver :: enum {