Occlusion culling algorithm based on recursive descend (#13104)

Co-authored-by: DS <vorunbekannt75@web.de>
This commit is contained in:
x2048 2023-01-06 22:31:06 +01:00 committed by GitHub
parent 059f62d7d6
commit 2715cc8bf6
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11 changed files with 493 additions and 58 deletions

@ -623,6 +623,15 @@ update_last_checked (Last update check) string
# Ex: 5.5.0 is 005005000
update_last_known (Last known version update) int 0
# Type of occlusion_culler
# "loops" is the legacy algorithm with nested loops and O(N^3) complexity
# "bfs" is the new algorithm based on breadth-first-search and side culling
occlusion_culler (Occlusion Culler) enum bfs bfs,loops
# Use raytraced occlusion culling in the new culler.
# This flag enables use of raytraced occlusion culling test
enable_raytraced_culling (Enable Raytraced Culling) bool true
[*Server]
# Name of the player.

@ -561,6 +561,7 @@ void Client::step(float dtime)
block->mesh = nullptr;
if (r.mesh) {
block->solid_sides = r.solid_sides;
minimap_mapblock = r.mesh->moveMinimapMapblock();
if (minimap_mapblock == NULL)
do_mapper_update = false;

@ -28,9 +28,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
#include "settings.h"
#include "camera.h" // CameraModes
#include "util/basic_macros.h"
#include <algorithm>
#include "client/renderingengine.h"
#include <queue>
// struct MeshBufListList
void MeshBufListList::clear()
{
@ -60,6 +61,10 @@ void MeshBufListList::add(scene::IMeshBuffer *buf, v3s16 position, u8 layer)
list.emplace_back(l);
}
static void on_settings_changed(const std::string &name, void *data)
{
static_cast<ClientMap*>(data)->onSettingChanged(name);
}
// ClientMap
ClientMap::ClientMap(
@ -98,7 +103,24 @@ ClientMap::ClientMap(
m_cache_bilinear_filter = g_settings->getBool("bilinear_filter");
m_cache_anistropic_filter = g_settings->getBool("anisotropic_filter");
m_cache_transparency_sorting_distance = g_settings->getU16("transparency_sorting_distance");
m_new_occlusion_culler = g_settings->get("occlusion_culler") == "bfs";
g_settings->registerChangedCallback("occlusion_culler", on_settings_changed, this);
m_enable_raytraced_culling = g_settings->getBool("enable_raytraced_culling");
g_settings->registerChangedCallback("enable_raytraced_culling", on_settings_changed, this);
}
void ClientMap::onSettingChanged(const std::string &name)
{
if (name == "occlusion_culler")
m_new_occlusion_culler = g_settings->get("occlusion_culler") == "bfs";
if (name == "enable_raytraced_culling")
m_enable_raytraced_culling = g_settings->getBool("enable_raytraced_culling");
}
ClientMap::~ClientMap()
{
g_settings->deregisterChangedCallback("occlusion_culler", on_settings_changed, this);
g_settings->deregisterChangedCallback("enable_raytraced_culling", on_settings_changed, this);
}
void ClientMap::updateCamera(v3f pos, v3f dir, f32 fov, v3s16 offset)
@ -180,8 +202,290 @@ void ClientMap::getBlocksInViewRange(v3s16 cam_pos_nodes,
p_nodes_max.Z / MAP_BLOCKSIZE + 1);
}
class MapBlockFlags
{
public:
static constexpr u16 CHUNK_EDGE = 8;
static constexpr u16 CHUNK_MASK = CHUNK_EDGE - 1;
static constexpr std::size_t CHUNK_VOLUME = CHUNK_EDGE * CHUNK_EDGE * CHUNK_EDGE; // volume of a chunk
MapBlockFlags(v3s16 min_pos, v3s16 max_pos)
: min_pos(min_pos), volume((max_pos - min_pos) / CHUNK_EDGE + 1)
{
chunks.resize(volume.X * volume.Y * volume.Z);
}
class Chunk
{
public:
inline u8 &getBits(v3s16 pos)
{
std::size_t address = getAddress(pos);
return bits[address];
}
private:
inline std::size_t getAddress(v3s16 pos) {
std::size_t address = (pos.X & CHUNK_MASK) + (pos.Y & CHUNK_MASK) * CHUNK_EDGE + (pos.Z & CHUNK_MASK) * (CHUNK_EDGE * CHUNK_EDGE);
return address;
}
std::array<u8, CHUNK_VOLUME> bits;
};
Chunk &getChunk(v3s16 pos)
{
v3s16 delta = (pos - min_pos) / CHUNK_EDGE;
std::size_t address = delta.X + delta.Y * volume.X + delta.Z * volume.X * volume.Y;
Chunk *chunk = chunks[address].get();
if (!chunk) {
chunk = new Chunk();
chunks[address].reset(chunk);
}
return *chunk;
}
private:
std::vector<std::unique_ptr<Chunk>> chunks;
v3s16 min_pos;
v3s16 volume;
};
void ClientMap::updateDrawList()
{
if (m_new_occlusion_culler) {
ScopeProfiler sp(g_profiler, "CM::updateDrawList()", SPT_AVG);
m_needs_update_drawlist = false;
for (auto &i : m_drawlist) {
MapBlock *block = i.second;
block->refDrop();
}
m_drawlist.clear();
v3s16 cam_pos_nodes = floatToInt(m_camera_position, BS);
v3s16 p_blocks_min;
v3s16 p_blocks_max;
getBlocksInViewRange(cam_pos_nodes, &p_blocks_min, &p_blocks_max);
// Number of blocks occlusion culled
u32 blocks_occlusion_culled = 0;
// Blocks visited by the algorithm
u32 blocks_visited = 0;
// Block sides that were not traversed
u32 sides_skipped = 0;
// No occlusion culling when free_move is on and camera is inside ground
bool occlusion_culling_enabled = true;
if (m_control.allow_noclip) {
MapNode n = getNode(cam_pos_nodes);
if (n.getContent() == CONTENT_IGNORE || m_nodedef->get(n).solidness == 2)
occlusion_culling_enabled = false;
}
v3s16 camera_block = getContainerPos(cam_pos_nodes, MAP_BLOCKSIZE);
m_drawlist = std::map<v3s16, MapBlock*, MapBlockComparer>(MapBlockComparer(camera_block));
auto is_frustum_culled = m_client->getCamera()->getFrustumCuller();
// Uncomment to debug occluded blocks in the wireframe mode
// TODO: Include this as a flag for an extended debugging setting
// if (occlusion_culling_enabled && m_control.show_wireframe)
// occlusion_culling_enabled = porting::getTimeS() & 1;
std::queue<v3s16> blocks_to_consider;
// Bits per block:
// [ visited | 0 | 0 | 0 | 0 | Z visible | Y visible | X visible ]
MapBlockFlags blocks_seen(p_blocks_min, p_blocks_max);
// Start breadth-first search with the block the camera is in
blocks_to_consider.push(camera_block);
blocks_seen.getChunk(camera_block).getBits(camera_block) = 0x07; // mark all sides as visible
// Recursively walk the space and pick mapblocks for drawing
while (blocks_to_consider.size() > 0) {
v3s16 block_coord = blocks_to_consider.front();
blocks_to_consider.pop();
auto &flags = blocks_seen.getChunk(block_coord).getBits(block_coord);
// Only visit each block once (it may have been queued up to three times)
if ((flags & 0x80) == 0x80)
continue;
flags |= 0x80;
blocks_visited++;
// Get the sector, block and mesh
MapSector *sector = this->getSectorNoGenerate(v2s16(block_coord.X, block_coord.Z));
if (!sector)
continue;
MapBlock *block = sector->getBlockNoCreateNoEx(block_coord.Y);
MapBlockMesh *mesh = block ? block->mesh : nullptr;
// Calculate the coordinates for range and frutum culling
v3f mesh_sphere_center;
f32 mesh_sphere_radius;
v3s16 block_pos_nodes = block_coord * MAP_BLOCKSIZE;
if (mesh) {
mesh_sphere_center = intToFloat(block_pos_nodes, BS)
+ mesh->getBoundingSphereCenter();
mesh_sphere_radius = mesh->getBoundingRadius();
}
else {
mesh_sphere_center = intToFloat(block_pos_nodes, BS) + v3f((MAP_BLOCKSIZE * 0.5f - 0.5f) * BS);
mesh_sphere_radius = 0.0f;
}
// First, perform a simple distance check.
if (!m_control.range_all &&
mesh_sphere_center.getDistanceFrom(intToFloat(cam_pos_nodes, BS)) >
m_control.wanted_range * BS + mesh_sphere_radius)
continue; // Out of range, skip.
// Frustum culling
// Only do coarse culling here, to account for fast camera movement.
// This is needed because this function is not called every frame.
float frustum_cull_extra_radius = 300.0f;
if (is_frustum_culled(mesh_sphere_center,
mesh_sphere_radius + frustum_cull_extra_radius))
continue;
// Calculate the vector from the camera block to the current block
// We use it to determine through which sides of the current block we can continue the search
v3s16 look = block_coord - camera_block;
// Occluded near sides will further occlude the far sides
u8 visible_outer_sides = flags & 0x07;
// Raytraced occlusion culling - send rays from the camera to the block's corners
if (occlusion_culling_enabled && m_enable_raytraced_culling &&
block && mesh &&
visible_outer_sides != 0x07 && isBlockOccluded(block, cam_pos_nodes)) {
blocks_occlusion_culled++;
continue;
}
// The block is visible, add to the draw list
if (mesh) {
// Add to set
block->refGrab();
m_drawlist[block_coord] = block;
}
// Decide which sides to traverse next or to block away
// First, find the near sides that would occlude the far sides
// * A near side can itself be occluded by a nearby block (the test above ^^)
// * A near side can be visible but fully opaque by itself (e.g. ground at the 0 level)
// mesh solid sides are +Z-Z+Y-Y+X-X
// if we are inside the block's coordinates on an axis,
// treat these sides as opaque, as they should not allow to reach the far sides
u8 block_inner_sides = (look.X == 0 ? 3 : 0) |
(look.Y == 0 ? 12 : 0) |
(look.Z == 0 ? 48 : 0);
// get the mask for the sides that are relevant based on the direction
u8 near_inner_sides = (look.X > 0 ? 1 : 2) |
(look.Y > 0 ? 4 : 8) |
(look.Z > 0 ? 16 : 32);
// This bitset is +Z-Z+Y-Y+X-X (See MapBlockMesh), and axis is XYZ.
// Get he block's transparent sides
u8 transparent_sides = (occlusion_culling_enabled && block) ? ~block->solid_sides : 0x3F;
// compress block transparent sides to ZYX mask of see-through axes
u8 near_transparency = (block_inner_sides == 0x3F) ? near_inner_sides : (transparent_sides & near_inner_sides);
// when we are inside the camera block, do not block any sides
if (block_inner_sides == 0x3F)
block_inner_sides = 0;
near_transparency &= ~block_inner_sides & 0x3F;
near_transparency |= (near_transparency >> 1);
near_transparency = (near_transparency & 1) |
((near_transparency >> 1) & 2) |
((near_transparency >> 2) & 4);
// combine with known visible sides that matter
near_transparency &= visible_outer_sides;
// The rule for any far side to be visible:
// * Any of the adjacent near sides is transparent (different axes)
// * The opposite near side (same axis) is transparent, if it is the dominant axis of the look vector
// Calculate vector from camera to mapblock center. Because we only need relation between
// coordinates we scale by 2 to avoid precision loss.
v3s16 precise_look = 2 * (block_pos_nodes - cam_pos_nodes) + MAP_BLOCKSIZE - 1;
// dominant axis flag
u8 dominant_axis = (abs(precise_look.X) > abs(precise_look.Y) && abs(precise_look.X) > abs(precise_look.Z)) |
((abs(precise_look.Y) > abs(precise_look.Z) && abs(precise_look.Y) > abs(precise_look.X)) << 1) |
((abs(precise_look.Z) > abs(precise_look.X) && abs(precise_look.Z) > abs(precise_look.Y)) << 2);
// Queue next blocks for processing:
// - Examine "far" sides of the current blocks, i.e. never move towards the camera
// - Only traverse the sides that are not occluded
// - Only traverse the sides that are not opaque
// When queueing, mark the relevant side on the next block as 'visible'
for (s16 axis = 0; axis < 3; axis++) {
// Select a bit from transparent_sides for the side
u8 far_side_mask = 1 << (2 * axis);
// axis flag
u8 my_side = 1 << axis;
u8 adjacent_sides = my_side ^ 0x07;
auto traverse_far_side = [&](s8 next_pos_offset) {
// far side is visible if adjacent near sides are transparent, or if opposite side on dominant axis is transparent
bool side_visible = ((near_transparency & adjacent_sides) | (near_transparency & my_side & dominant_axis)) != 0;
side_visible = side_visible && ((far_side_mask & transparent_sides) != 0);
v3s16 next_pos = block_coord;
next_pos[axis] += next_pos_offset;
// If a side is a see-through, mark the next block's side as visible, and queue
if (side_visible) {
auto &next_flags = blocks_seen.getChunk(next_pos).getBits(next_pos);
next_flags |= my_side;
blocks_to_consider.push(next_pos);
}
else {
sides_skipped++;
}
};
// Test the '-' direction of the axis
if (look[axis] <= 0 && block_coord[axis] > p_blocks_min[axis])
traverse_far_side(-1);
// Test the '+' direction of the axis
far_side_mask <<= 1;
if (look[axis] >= 0 && block_coord[axis] < p_blocks_max[axis])
traverse_far_side(+1);
}
}
g_profiler->avg("MapBlocks occlusion culled [#]", blocks_occlusion_culled);
g_profiler->avg("MapBlocks sides skipped [#]", sides_skipped);
g_profiler->avg("MapBlocks examined [#]", blocks_visited);
g_profiler->avg("MapBlocks drawn [#]", m_drawlist.size());
}
else {
ScopeProfiler sp(g_profiler, "CM::updateDrawList()", SPT_AVG);
m_needs_update_drawlist = false;
@ -297,6 +601,70 @@ void ClientMap::updateDrawList()
g_profiler->avg("MapBlocks occlusion culled [#]", blocks_occlusion_culled);
g_profiler->avg("MapBlocks drawn [#]", m_drawlist.size());
g_profiler->avg("MapBlocks loaded [#]", blocks_loaded);
}
}
void ClientMap::touchMapBlocks()
{
if (!m_new_occlusion_culler)
return;
v3s16 cam_pos_nodes = floatToInt(m_camera_position, BS);
v3s16 p_blocks_min;
v3s16 p_blocks_max;
getBlocksInViewRange(cam_pos_nodes, &p_blocks_min, &p_blocks_max);
// Number of blocks currently loaded by the client
u32 blocks_loaded = 0;
// Number of blocks with mesh in rendering range
u32 blocks_in_range_with_mesh = 0;
for (const auto &sector_it : m_sectors) {
MapSector *sector = sector_it.second;
v2s16 sp = sector->getPos();
blocks_loaded += sector->size();
if (!m_control.range_all) {
if (sp.X < p_blocks_min.X || sp.X > p_blocks_max.X ||
sp.Y < p_blocks_min.Z || sp.Y > p_blocks_max.Z)
continue;
}
MapBlockVect sectorblocks;
sector->getBlocks(sectorblocks);
/*
Loop through blocks in sector
*/
for (MapBlock *block : sectorblocks) {
/*
Compare block position to camera position, skip
if not seen on display
*/
if (!block->mesh) {
// Ignore if mesh doesn't exist
continue;
}
v3f mesh_sphere_center = intToFloat(block->getPosRelative(), BS)
+ block->mesh->getBoundingSphereCenter();
f32 mesh_sphere_radius = block->mesh->getBoundingRadius();
// First, perform a simple distance check.
if (!m_control.range_all &&
mesh_sphere_center.getDistanceFrom(intToFloat(cam_pos_nodes, BS)) >
m_control.wanted_range * BS + mesh_sphere_radius)
continue; // Out of range, skip.
// Keep the block alive as long as it is in range.
block->resetUsageTimer();
blocks_in_range_with_mesh++;
}
}
g_profiler->avg("MapBlock meshes in range [#]", blocks_in_range_with_mesh);
g_profiler->avg("MapBlocks loaded [#]", blocks_loaded);
}
void ClientMap::renderMap(video::IVideoDriver* driver, s32 pass)

@ -76,7 +76,7 @@ public:
s32 id
);
virtual ~ClientMap() = default;
virtual ~ClientMap();
bool maySaveBlocks() override
{
@ -116,6 +116,8 @@ public:
void getBlocksInViewRange(v3s16 cam_pos_nodes,
v3s16 *p_blocks_min, v3s16 *p_blocks_max, float range=-1.0f);
void updateDrawList();
// @brief Calculate statistics about the map and keep the blocks alive
void touchMapBlocks();
void updateDrawListShadow(v3f shadow_light_pos, v3f shadow_light_dir, float radius, float length);
// Returns true if draw list needs updating before drawing the next frame.
bool needsUpdateDrawList() { return m_needs_update_drawlist; }
@ -136,11 +138,14 @@ public:
f32 getWantedRange() const { return m_control.wanted_range; }
f32 getCameraFov() const { return m_camera_fov; }
void onSettingChanged(const std::string &name);
private:
// update the vertex order in transparent mesh buffers
void updateTransparentMeshBuffers();
// Orders blocks by distance to the camera
class MapBlockComparer
{
@ -205,4 +210,7 @@ private:
bool m_cache_bilinear_filter;
bool m_cache_anistropic_filter;
u16 m_cache_transparency_sorting_distance;
bool m_new_occlusion_culler;
bool m_enable_raytraced_culling;
};

@ -696,6 +696,7 @@ struct GameRunData {
float damage_flash;
float update_draw_list_timer;
float touch_blocks_timer;
f32 fog_range;
@ -4030,6 +4031,9 @@ void Game::updateFrame(ProfilerGraph *graph, RunStats *stats, f32 dtime,
changed much
*/
runData.update_draw_list_timer += dtime;
runData.touch_blocks_timer += dtime;
bool draw_list_updated = false;
float update_draw_list_delta = 0.2f;
@ -4041,6 +4045,12 @@ void Game::updateFrame(ProfilerGraph *graph, RunStats *stats, f32 dtime,
runData.update_draw_list_timer = 0;
client->getEnv().getClientMap().updateDrawList();
runData.update_draw_list_last_cam_dir = camera_direction;
draw_list_updated = true;
}
if (runData.touch_blocks_timer > update_draw_list_delta && !draw_list_updated) {
client->getEnv().getClientMap().touchMapBlocks();
runData.touch_blocks_timer = 0;
}
if (RenderingEngine::get_shadow_renderer()) {

@ -1582,3 +1582,31 @@ video::SColor encode_light(u16 light, u8 emissive_light)
float b = (day + night) / 2;
return video::SColor(r, b, b, b);
}
u8 get_solid_sides(MeshMakeData *data)
{
v3s16 blockpos_nodes = data->m_blockpos * MAP_BLOCKSIZE;
const NodeDefManager *ndef = data->m_client->ndef();
u8 result = 0x3F; // all sides solid;
for (s16 i = 0; i < MAP_BLOCKSIZE && result != 0; i++)
for (s16 j = 0; j < MAP_BLOCKSIZE && result != 0; j++) {
v3s16 positions[6] = {
v3s16(0, i, j),
v3s16(MAP_BLOCKSIZE - 1, i, j),
v3s16(i, 0, j),
v3s16(i, MAP_BLOCKSIZE - 1, j),
v3s16(i, j, 0),
v3s16(i, j, MAP_BLOCKSIZE - 1)
};
for (u8 k = 0; k < 6; k++) {
const MapNode &top = data->m_vmanip.getNodeRefUnsafe(blockpos_nodes + positions[k]);
if (ndef->get(top).solidness != 2)
result &= ~(1 << k);
}
}
return result;
}

@ -340,3 +340,8 @@ void final_color_blend(video::SColor *result,
// TileFrame vector copy cost very much to client
void getNodeTileN(MapNode mn, const v3s16 &p, u8 tileindex, MeshMakeData *data, TileSpec &tile);
void getNodeTile(MapNode mn, const v3s16 &p, const v3s16 &dir, MeshMakeData *data, TileSpec &tile);
/// Return bitset of the sides of the mapblock that consist of solid nodes only
/// Bits:
/// 0 0 -Z +Z -X +X -Y +Y
u8 get_solid_sides(MeshMakeData *data);

@ -299,6 +299,7 @@ void MeshUpdateWorkerThread::doUpdate()
MeshUpdateResult r;
r.p = q->p;
r.mesh = mesh_new;
r.solid_sides = get_solid_sides(q->data);
r.ack_block_to_server = q->ack_block_to_server;
r.urgent = q->urgent;

@ -111,6 +111,7 @@ struct MeshUpdateResult
{
v3s16 p = v3s16(-1338, -1338, -1338);
MapBlockMesh *mesh = nullptr;
u8 solid_sides = 0;
bool ack_block_to_server = false;
bool urgent = false;

@ -66,6 +66,8 @@ void set_default_settings()
settings->setDefault("max_out_chat_queue_size", "20");
settings->setDefault("pause_on_lost_focus", "false");
settings->setDefault("enable_split_login_register", "true");
settings->setDefault("occlusion_culler", "bfs");
settings->setDefault("enable_raytraced_culling", "true");
settings->setDefault("chat_weblink_color", "#8888FF");
// Keymap

@ -469,6 +469,8 @@ public:
bool contents_cached = false;
// True if we never want to cache content types for this block
bool do_not_cache_contents = false;
// marks the sides which are opaque: 00+Z-Z+Y-Y+X-X
u8 solid_sides {0};
private:
/*