godot/servers/rendering/renderer_rd/shaders/particles.glsl
reduz 906882ee66 Split particle shader entry points
* Particle shaders now have start() and process()
* Particle collision happens between them.
* The RESTART property is kept, so porting an old shader is still possible.

This fixes the problem of particle collisions not functioning on the first particle frame.
2021-04-17 12:22:55 -03:00

546 lines
15 KiB
GLSL

#[compute]
#version 450
#VERSION_DEFINES
layout(local_size_x = 64, local_size_y = 1, local_size_z = 1) in;
#define SAMPLER_NEAREST_CLAMP 0
#define SAMPLER_LINEAR_CLAMP 1
#define SAMPLER_NEAREST_WITH_MIPMAPS_CLAMP 2
#define SAMPLER_LINEAR_WITH_MIPMAPS_CLAMP 3
#define SAMPLER_NEAREST_WITH_MIPMAPS_ANISOTROPIC_CLAMP 4
#define SAMPLER_LINEAR_WITH_MIPMAPS_ANISOTROPIC_CLAMP 5
#define SAMPLER_NEAREST_REPEAT 6
#define SAMPLER_LINEAR_REPEAT 7
#define SAMPLER_NEAREST_WITH_MIPMAPS_REPEAT 8
#define SAMPLER_LINEAR_WITH_MIPMAPS_REPEAT 9
#define SAMPLER_NEAREST_WITH_MIPMAPS_ANISOTROPIC_REPEAT 10
#define SAMPLER_LINEAR_WITH_MIPMAPS_ANISOTROPIC_REPEAT 11
/* SET 0: GLOBAL DATA */
layout(set = 0, binding = 1) uniform sampler material_samplers[12];
layout(set = 0, binding = 2, std430) restrict readonly buffer GlobalVariableData {
vec4 data[];
}
global_variables;
/* Set 1: FRAME AND PARTICLE DATA */
// a frame history is kept for trail deterministic behavior
#define MAX_ATTRACTORS 32
#define ATTRACTOR_TYPE_SPHERE 0
#define ATTRACTOR_TYPE_BOX 1
#define ATTRACTOR_TYPE_VECTOR_FIELD 2
struct Attractor {
mat4 transform;
vec3 extents; //exents or radius
uint type;
uint texture_index; //texture index for vector field
float strength;
float attenuation;
float directionality;
};
#define MAX_COLLIDERS 32
#define COLLIDER_TYPE_SPHERE 0
#define COLLIDER_TYPE_BOX 1
#define COLLIDER_TYPE_SDF 2
#define COLLIDER_TYPE_HEIGHT_FIELD 3
struct Collider {
mat4 transform;
vec3 extents; //exents or radius
uint type;
uint texture_index; //texture index for vector field
float scale;
uint pad[2];
};
struct FrameParams {
bool emitting;
float system_phase;
float prev_system_phase;
uint cycle;
float explosiveness;
float randomness;
float time;
float delta;
uint random_seed;
uint attractor_count;
uint collider_count;
float particle_size;
mat4 emission_transform;
Attractor attractors[MAX_ATTRACTORS];
Collider colliders[MAX_COLLIDERS];
};
layout(set = 1, binding = 0, std430) restrict buffer FrameHistory {
FrameParams data[];
}
frame_history;
struct ParticleData {
mat4 xform;
vec3 velocity;
bool is_active;
vec4 color;
vec4 custom;
};
layout(set = 1, binding = 1, std430) restrict buffer Particles {
ParticleData data[];
}
particles;
#define EMISSION_FLAG_HAS_POSITION 1
#define EMISSION_FLAG_HAS_ROTATION_SCALE 2
#define EMISSION_FLAG_HAS_VELOCITY 4
#define EMISSION_FLAG_HAS_COLOR 8
#define EMISSION_FLAG_HAS_CUSTOM 16
struct ParticleEmission {
mat4 xform;
vec3 velocity;
uint flags;
vec4 color;
vec4 custom;
};
layout(set = 1, binding = 2, std430) restrict buffer SourceEmission {
int particle_count;
uint pad0;
uint pad1;
uint pad2;
ParticleEmission data[];
}
src_particles;
layout(set = 1, binding = 3, std430) restrict buffer DestEmission {
int particle_count;
int particle_max;
uint pad1;
uint pad2;
ParticleEmission data[];
}
dst_particles;
/* SET 2: COLLIDER/ATTRACTOR TEXTURES */
#define MAX_3D_TEXTURES 7
layout(set = 2, binding = 0) uniform texture3D sdf_vec_textures[MAX_3D_TEXTURES];
layout(set = 2, binding = 1) uniform texture2D height_field_texture;
/* SET 3: MATERIAL */
#ifdef MATERIAL_UNIFORMS_USED
layout(set = 3, binding = 0, std140) uniform MaterialUniforms{
#MATERIAL_UNIFORMS
} material;
#endif
layout(push_constant, binding = 0, std430) uniform Params {
float lifetime;
bool clear;
uint total_particles;
uint trail_size;
bool use_fractional_delta;
bool sub_emitter_mode;
bool can_emit;
uint pad;
}
params;
uint hash(uint x) {
x = ((x >> uint(16)) ^ x) * uint(0x45d9f3b);
x = ((x >> uint(16)) ^ x) * uint(0x45d9f3b);
x = (x >> uint(16)) ^ x;
return x;
}
bool emit_subparticle(mat4 p_xform, vec3 p_velocity, vec4 p_color, vec4 p_custom, uint p_flags) {
if (!params.can_emit) {
return false;
}
bool valid = false;
int dst_index = atomicAdd(dst_particles.particle_count, 1);
if (dst_index >= dst_particles.particle_max) {
atomicAdd(dst_particles.particle_count, -1);
return false;
}
dst_particles.data[dst_index].xform = p_xform;
dst_particles.data[dst_index].velocity = p_velocity;
dst_particles.data[dst_index].color = p_color;
dst_particles.data[dst_index].custom = p_custom;
dst_particles.data[dst_index].flags = p_flags;
return true;
}
#GLOBALS
void main() {
uint particle = gl_GlobalInvocationID.x;
if (particle >= params.total_particles * params.trail_size) {
return; //discard
}
uint index = particle / params.trail_size;
uint frame = (particle % params.trail_size);
#define FRAME frame_history.data[frame]
#define PARTICLE particles.data[particle]
bool apply_forces = true;
bool apply_velocity = true;
float local_delta = FRAME.delta;
float mass = 1.0;
bool restart = false;
bool restart_position = false;
bool restart_rotation_scale = false;
bool restart_velocity = false;
bool restart_color = false;
bool restart_custom = false;
if (params.clear) {
PARTICLE.color = vec4(1.0);
PARTICLE.custom = vec4(0.0);
PARTICLE.velocity = vec3(0.0);
PARTICLE.is_active = false;
PARTICLE.xform = mat4(
vec4(1.0, 0.0, 0.0, 0.0),
vec4(0.0, 1.0, 0.0, 0.0),
vec4(0.0, 0.0, 1.0, 0.0),
vec4(0.0, 0.0, 0.0, 1.0));
}
bool collided = false;
vec3 collision_normal = vec3(0.0);
float collision_depth = 0.0;
vec3 attractor_force = vec3(0.0);
#if !defined(DISABLE_VELOCITY)
if (PARTICLE.is_active) {
PARTICLE.xform[3].xyz += PARTICLE.velocity * local_delta;
}
#endif
/* Process physics if active */
if (params.sub_emitter_mode) {
if (!PARTICLE.is_active) {
int src_index = atomicAdd(src_particles.particle_count, -1) - 1;
if (src_index >= 0) {
PARTICLE.is_active = true;
restart = true;
if (bool(src_particles.data[src_index].flags & EMISSION_FLAG_HAS_POSITION)) {
PARTICLE.xform[3] = src_particles.data[src_index].xform[3];
} else {
PARTICLE.xform[3] = vec4(0, 0, 0, 1);
restart_position = true;
}
if (bool(src_particles.data[src_index].flags & EMISSION_FLAG_HAS_ROTATION_SCALE)) {
PARTICLE.xform[0] = src_particles.data[src_index].xform[0];
PARTICLE.xform[1] = src_particles.data[src_index].xform[1];
PARTICLE.xform[2] = src_particles.data[src_index].xform[2];
} else {
PARTICLE.xform[0] = vec4(1, 0, 0, 0);
PARTICLE.xform[1] = vec4(0, 1, 0, 0);
PARTICLE.xform[2] = vec4(0, 0, 1, 0);
restart_rotation_scale = true;
}
if (bool(src_particles.data[src_index].flags & EMISSION_FLAG_HAS_VELOCITY)) {
PARTICLE.velocity = src_particles.data[src_index].velocity;
} else {
PARTICLE.velocity = vec3(0);
restart_velocity = true;
}
if (bool(src_particles.data[src_index].flags & EMISSION_FLAG_HAS_COLOR)) {
PARTICLE.color = src_particles.data[src_index].color;
} else {
PARTICLE.color = vec4(1);
restart_color = true;
}
if (bool(src_particles.data[src_index].flags & EMISSION_FLAG_HAS_CUSTOM)) {
PARTICLE.custom = src_particles.data[src_index].custom;
} else {
PARTICLE.custom = vec4(0);
restart_custom = true;
}
}
}
} else if (FRAME.emitting) {
float restart_phase = float(index) / float(params.total_particles);
if (FRAME.randomness > 0.0) {
uint seed = FRAME.cycle;
if (restart_phase >= FRAME.system_phase) {
seed -= uint(1);
}
seed *= uint(params.total_particles);
seed += uint(index);
float random = float(hash(seed) % uint(65536)) / 65536.0;
restart_phase += FRAME.randomness * random * 1.0 / float(params.total_particles);
}
restart_phase *= (1.0 - FRAME.explosiveness);
if (FRAME.system_phase > FRAME.prev_system_phase) {
// restart_phase >= prev_system_phase is used so particles emit in the first frame they are processed
if (restart_phase >= FRAME.prev_system_phase && restart_phase < FRAME.system_phase) {
restart = true;
if (params.use_fractional_delta) {
local_delta = (FRAME.system_phase - restart_phase) * params.lifetime;
}
}
} else if (FRAME.delta > 0.0) {
if (restart_phase >= FRAME.prev_system_phase) {
restart = true;
if (params.use_fractional_delta) {
local_delta = (1.0 - restart_phase + FRAME.system_phase) * params.lifetime;
}
} else if (restart_phase < FRAME.system_phase) {
restart = true;
if (params.use_fractional_delta) {
local_delta = (FRAME.system_phase - restart_phase) * params.lifetime;
}
}
}
uint current_cycle = FRAME.cycle;
if (FRAME.system_phase < restart_phase) {
current_cycle -= uint(1);
}
uint particle_number = current_cycle * uint(params.total_particles) + particle;
if (restart) {
PARTICLE.is_active = FRAME.emitting;
restart_position = true;
restart_rotation_scale = true;
restart_velocity = true;
restart_color = true;
restart_custom = true;
}
}
if (restart && PARTICLE.is_active) {
#CODE : START
}
if (PARTICLE.is_active) {
for (uint i = 0; i < FRAME.attractor_count; i++) {
vec3 dir;
float amount;
vec3 rel_vec = PARTICLE.xform[3].xyz - FRAME.attractors[i].transform[3].xyz;
vec3 local_pos = rel_vec * mat3(FRAME.attractors[i].transform);
switch (FRAME.attractors[i].type) {
case ATTRACTOR_TYPE_SPHERE: {
dir = normalize(rel_vec);
float d = length(local_pos) / FRAME.attractors[i].extents.x;
if (d > 1.0) {
continue;
}
amount = max(0.0, 1.0 - d);
} break;
case ATTRACTOR_TYPE_BOX: {
dir = normalize(rel_vec);
vec3 abs_pos = abs(local_pos / FRAME.attractors[i].extents);
float d = max(abs_pos.x, max(abs_pos.y, abs_pos.z));
if (d > 1.0) {
continue;
}
amount = max(0.0, 1.0 - d);
} break;
case ATTRACTOR_TYPE_VECTOR_FIELD: {
vec3 uvw_pos = (local_pos / FRAME.attractors[i].extents) * 2.0 - 1.0;
if (any(lessThan(uvw_pos, vec3(0.0))) || any(greaterThan(uvw_pos, vec3(1.0)))) {
continue;
}
vec3 s = texture(sampler3D(sdf_vec_textures[FRAME.attractors[i].texture_index], material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos).xyz;
dir = mat3(FRAME.attractors[i].transform) * normalize(s); //revert direction
amount = length(s);
} break;
}
amount = pow(amount, FRAME.attractors[i].attenuation);
dir = normalize(mix(dir, FRAME.attractors[i].transform[2].xyz, FRAME.attractors[i].directionality));
attractor_force -= amount * dir * FRAME.attractors[i].strength;
}
float particle_size = FRAME.particle_size;
#ifdef USE_COLLISON_SCALE
particle_size *= dot(vec3(length(PARTICLE.xform[0].xyz), length(PARTICLE.xform[1].xyz), length(PARTICLE.xform[2].xyz)), vec3(0.33333333333));
#endif
for (uint i = 0; i < FRAME.collider_count; i++) {
vec3 normal;
float depth;
bool col = false;
vec3 rel_vec = PARTICLE.xform[3].xyz - FRAME.colliders[i].transform[3].xyz;
vec3 local_pos = rel_vec * mat3(FRAME.colliders[i].transform);
switch (FRAME.colliders[i].type) {
case COLLIDER_TYPE_SPHERE: {
float d = length(rel_vec) - (particle_size + FRAME.colliders[i].extents.x);
if (d < 0.0) {
col = true;
depth = -d;
normal = normalize(rel_vec);
}
} break;
case COLLIDER_TYPE_BOX: {
vec3 abs_pos = abs(local_pos);
vec3 sgn_pos = sign(local_pos);
if (any(greaterThan(abs_pos, FRAME.colliders[i].extents))) {
//point outside box
vec3 closest = min(abs_pos, FRAME.colliders[i].extents);
vec3 rel = abs_pos - closest;
depth = length(rel) - particle_size;
if (depth < 0.0) {
col = true;
normal = mat3(FRAME.colliders[i].transform) * (normalize(rel) * sgn_pos);
depth = -depth;
}
} else {
//point inside box
vec3 axis_len = FRAME.colliders[i].extents - abs_pos;
// there has to be a faster way to do this?
if (all(lessThan(axis_len.xx, axis_len.yz))) {
normal = vec3(1, 0, 0);
} else if (all(lessThan(axis_len.yy, axis_len.xz))) {
normal = vec3(0, 1, 0);
} else {
normal = vec3(0, 0, 1);
}
col = true;
depth = dot(normal * axis_len, vec3(1)) + particle_size;
normal = mat3(FRAME.colliders[i].transform) * (normal * sgn_pos);
}
} break;
case COLLIDER_TYPE_SDF: {
vec3 apos = abs(local_pos);
float extra_dist = 0.0;
if (any(greaterThan(apos, FRAME.colliders[i].extents))) { //outside
vec3 mpos = min(apos, FRAME.colliders[i].extents);
extra_dist = distance(mpos, apos);
}
if (extra_dist > particle_size) {
continue;
}
vec3 uvw_pos = (local_pos / FRAME.colliders[i].extents) * 0.5 + 0.5;
float s = texture(sampler3D(sdf_vec_textures[FRAME.colliders[i].texture_index], material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos).r;
s *= FRAME.colliders[i].scale;
s += extra_dist;
if (s < particle_size) {
col = true;
depth = particle_size - s;
const float EPSILON = 0.001;
normal = mat3(FRAME.colliders[i].transform) *
normalize(
vec3(
texture(sampler3D(sdf_vec_textures[FRAME.colliders[i].texture_index], material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos + vec3(EPSILON, 0.0, 0.0)).r - texture(sampler3D(sdf_vec_textures[FRAME.colliders[i].texture_index], material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos - vec3(EPSILON, 0.0, 0.0)).r,
texture(sampler3D(sdf_vec_textures[FRAME.colliders[i].texture_index], material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos + vec3(0.0, EPSILON, 0.0)).r - texture(sampler3D(sdf_vec_textures[FRAME.colliders[i].texture_index], material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos - vec3(0.0, EPSILON, 0.0)).r,
texture(sampler3D(sdf_vec_textures[FRAME.colliders[i].texture_index], material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos + vec3(0.0, 0.0, EPSILON)).r - texture(sampler3D(sdf_vec_textures[FRAME.colliders[i].texture_index], material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos - vec3(0.0, 0.0, EPSILON)).r));
}
} break;
case COLLIDER_TYPE_HEIGHT_FIELD: {
vec3 local_pos_bottom = local_pos;
local_pos_bottom.y -= particle_size;
if (any(greaterThan(abs(local_pos_bottom), FRAME.colliders[i].extents))) {
continue;
}
const float DELTA = 1.0 / 8192.0;
vec3 uvw_pos = vec3(local_pos_bottom / FRAME.colliders[i].extents) * 0.5 + 0.5;
float y = 1.0 - texture(sampler2D(height_field_texture, material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos.xz).r;
if (y > uvw_pos.y) {
//inside heightfield
vec3 pos1 = (vec3(uvw_pos.x, y, uvw_pos.z) * 2.0 - 1.0) * FRAME.colliders[i].extents;
vec3 pos2 = (vec3(uvw_pos.x + DELTA, 1.0 - texture(sampler2D(height_field_texture, material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos.xz + vec2(DELTA, 0)).r, uvw_pos.z) * 2.0 - 1.0) * FRAME.colliders[i].extents;
vec3 pos3 = (vec3(uvw_pos.x, 1.0 - texture(sampler2D(height_field_texture, material_samplers[SAMPLER_LINEAR_CLAMP]), uvw_pos.xz + vec2(0, DELTA)).r, uvw_pos.z + DELTA) * 2.0 - 1.0) * FRAME.colliders[i].extents;
normal = normalize(cross(pos1 - pos2, pos1 - pos3));
float local_y = (vec3(local_pos / FRAME.colliders[i].extents) * 0.5 + 0.5).y;
col = true;
depth = dot(normal, pos1) - dot(normal, local_pos_bottom);
}
} break;
}
if (col) {
if (!collided) {
collided = true;
collision_normal = normal;
collision_depth = depth;
} else {
vec3 c = collision_normal * collision_depth;
c += normal * max(0.0, depth - dot(normal, c));
collision_normal = normalize(c);
collision_depth = length(c);
}
}
}
}
if (PARTICLE.is_active) {
#CODE : PROCESS
}
}