As discussed with Tim on irc: Here is a quick fix for the memory-hungry tile
manager. Due to bugs in FGNewCache, old tiles were never deleted.
I left the timestamp-updates in the cull-traversal. but imho things work
just as well when timestamps are updated in FGNewCache::insert_tile() and
FGNewCache::get_tile()
The LOD far range on the tile entry scenegraph node was initialized to
0. This meant that any traverals of active children that happened
before the tile manager updated the node would ignore the node
altogether. Among these is the groundcache traversal which was failing
at startup even though scenery was loaded.
Also added a function to dump scene graph nodes to files; very handy
in gdb.
Make an OSG file reader for .stg files.
New class flightgear::SceneryPager, which is a subclass
osg::DatabasePager to handle explicit delete requests.
Modify FGNewCache, FGTileEntry, and FGTileManager to use
SceneryPager. Mostly this involved removing the queues that talked to
FGTileLoader.
Calculate accurate tile timestamps from the time they are traversed in
the cull stage (which means that they are visible) instead of updating
them periodically.
Replace tile entry transform and range node with one LOD node
Some cleanup in tileentry.cxx, but mostly code to implement loading of tiles
and their models without reference to FGTileEntry or SGBucket structures.
Also, don't do deferred model loading; load them when the tile is loaded.
src/Scenery/tileentry.cxx: Jonathan Wagner:
Removes black dots by accounting for radius of nodes
when calculating visible nodes for traversal without removing the
optimization. Confirmed fix with a few people on IRC.
implement FGNasalModelData class for execution of XML <load> and <unload>
scripts. modelLoaded() is called by the model loader, and the destructor
on branch removal.
modelmgr.cxx:
tilemgr.cxx:
tileentry.[ch]xx:
make scenery and custom objects run their Nasal scripts on loading
and unloading. Let OBJECT_STATIC object not be cached.
Insert empty string as marker between FG_SCENERY path elements.
FG_SCENERY=A:B expands to [A/Terrain, A/Objects, "", B/Terrain, B/Objects, ""]
(assuming that both A/ and B/ have Terrain/ and Objects/ subdirs).
tileentry.cxx -- FGTileEntry::load():
Check all tile dirs in FG_SCENERY from left to right: add all objects
to the scenery until a terrain tile was found: In this case read the
rest of that group (i.e. the Objects/ twin dir) and then stop scanning.
Better structuring of log messages & fix warnings.
sea tile, and finally process the objects. This guarantees that all objects
are placed relative to a valid tile center, rather than to the origin (0/0/0).
This is important for objects in sea tiles, and allows to display objects
of *.stg files that came sooner in FG_SCENERY.
I have done a valgrind run in flightgear. Just start it up and close it at the
fist change I had about half an hour later.
source-leak.diff:
Also two minor ones, but leaks ...
I have prepared a patch that:
- Introduces a FGTileMgr::scenery_available method which asks the tilemanager
if scenery for a given range around a lat/lon pair is already loaded and make
use of that method at some -9999 meter checks.
- Introduces a FGScenery::get_elevation_m method which queries the altitude at
a given position. In constrast to the groundcache functions this is the best
choice if you ask for one *single* altitude value. Make use of that thing in
AI/ATC classes and for the current views ground level. At the current views
part the groundcache is reused if possible.
- The computation of the 'current groundlevel' is no longer done on the
tilemanagers update since the required functions are now better seperated.
Alltogether it eliminates somehow redundant terrain level computations which
are now superseeded by that more finegrained functions and the existence of
the groundcache. Additionally it introduces an api to commonly required
functions which was very complex to do prevously.
2.
I made YASim query the the ground cache at the wrong place. This one fixed
this, one can now land the bo105 on top of the oracle buildings :)
3.
Is a followup of the scenery center update code: Register the scenery center
transform at the time it is put into the scene graph not at creation time.
4.
I held that part back from the past hitlist patch, because I hoped that it
will be sufficient (and the last one was in fact the biggest part) without.
As some test cases from Melchior showed me, it is not. We have additionally
to the wrong computed transform from the prevous patch some roundoff
problems. This patch adds some small tolerance to for the point in triangle
test.
... may be one even needs to increase the eps value further if starting at
some tile boundaries still fails.
5.
That is a big chunk.
Tested now for two days while hunting the second patch :) .
That is a partial rewrite of the groundcache to use its own datastructures for
that flat scenegraph in the cache. The basic advantage is, what Erik
suggested, to precompute some often used values of these triangles. Also
allmost all computations are now in double precision which should decrease
(hopefully fix), together with a similar tolerance for some point in triangle
tests, the problems with 'no ground below aircraft'.
I am playing with octrees for the groundcache, that will finally solve the
performance problem when high triangular count models end up in the
groundcache. This patch is also some prework for those octrees ...
I have done a patch to eliminate the jitter of 3D-objects near the viewpoint
(for example 3D cockpit objects).
The problem is the roundoff accuracy of the float values used in the
scenegraph together with the transforms of the eyepoint relative to the
scenery center.
The solution will be to move the scenery center near the view point.
This way floats relative accuracy is enough to show a stable picture.
To get that right I have introduced a transform node for the scenegraph which
is responsible for that shift and uses double values as long as possible.
The scenery subsystem now has a list of all those transforms required to place
objects in the world and will tell all those transforms that the scenery
center has changed when the set_scenery_center() of the scenery subsystem is
called.
The problem was not solvable by SGModelPlacement and SGLocation, since not all
objects, especially the scenery, are placed using these classes.
The first approach was to have the scenery center exactly at the eyepoint.
This works well for the cockpit.
But then the ground jitters a bit below the aircraft. With our default views
you can't see that, but that F-18 has a camera view below the left engine
intake with the nose gear and the ground in its field of view, here I could
see that.
Having the scenery center constant will still have this roundoff problems, but
like it is now too, the roundoff error here is exactly the same in each
frame, so you will not notice any jitter.
The real solution is now to keep the scenery center constant as long as it is
in a ball of 30m radius around the view point. If the scenery center is
outside this ball, just put it at the view point.
As a sideeffect of now beeing able to switch the scenery center in the whole
scenegraph with one function call, I was able to remove a one half of a
problem when switching views, where the scenery center was far off for one or
two frames past switching from one view to the next. Also included is a fix
to the other half of this problem, where the view position was not yet copied
into a view when it is switched (at least under glut). This was responsible
for the 'Error: ...' messages of the cloud subsystem when views were
switched.
The attached patch allows to put comments in *.stg files[1]. Lines with
# in the first column (and only there!) are skipped. This has no effect
on overall performance, but has two advantages:
A) possibility to temporarily comment out objects during scenery design,
(or to put other remarks there);
B) possibility to put marks like "# BEGIN" and "# END" there that allow
automated merging of local landmarks etc.
--
[1] actually, comments are possible now, too. But they aren't explicitly
handled and fgfs tries to parse words in "comments" piece by piece. Ugly!
[2] Idea by Chris METZLER, that I make already use of. I have a local
scenery dir for some tiles with extra objects, such as VOR/DME for
all of Austria. These are surrounded by "# BEGIN LOCAL" and "# END LOCAL",
and today I was able to merge the new 0.9.7 scenery with my locally
changed files. :-)
This is a patch to make display list usage optional. They are on by default.
Use --prop:/sim/rendering/use-display-list=false to use immediate mode.
There is also a change in exception handling in main.cxx and bootstrap.cxx
paging system much more robust when position change is very rapid and sporadic.
Recall that we must load 3d models in the main render thread because model
loading can trigger opengl calls (i.e. with texture loading) and all opengl
calls *must* happen in the main render thread.
To accomplish this we load the base tile in the pager thread and build a work
queue of external models that need to be loaded. We never allow a tile to be
paged out of the tile cache until all it's pending model loads are complete.
However, when changing position very rapidly, we can quickly create a huge
backlog of pending model loads because we are changing positions faster than we
can load the associated models for the existing tiles. The end result is
that tiles that are long out of range can't be removed because there is still
a huge backlog of pending model load requests and memory blows up.
This change being committed allows the tile paging system to remove tiles
if they are out of range, even when there are pending models to load. The
model loading code in the render thread can now check to see if the tile
exists and discard any model load request for tiles that no longer exist.
This situation should never occur in normal operation, but could occur in
"contrived" situations where an external script was rapidly changing
the simulator position to then be able to query FG terrain height, and doing
this for a large number of points that are distributed across a large area.
Wouldn't it be better to prepare the whole list of paths (or two
separate ones for Terrain/Objects if necessary) in FGGlobals::set_fg_scenery,
and to pass the vector<string>s to FGTileEntry::load? It doesn't seem to make
a lot of sense to split the path up, modify it, mount it together to one string
again, and then let FGTileEntry::load split it up again.
Here we go:
Main/globals.cxx
================
As fg_scenery is now a string_list, we don't need initialization. Furthermore,
this list is cleared with every set_fg_scenery() call.
ctor: create default dir from fg_root if necessary. Otherwise check all paths
of --fg-scenery/FG_SCENERY: If the path doesn't exist, ignore it. If it contains
a dir Terrain and/or Objects, then only add that to the list. If it contains
neither, then use the path as is.
Scenery/tileentry.cxx
=====================
Trivial: don't split a "base path", but use the given path_list as is.
(I considered a variable name "path_list" better suited than "search".)
Scenery/FGTileLoader.cxx
========================
No more fiddling with sub-paths. This has to be delivered by get_fg_scenery
already.
account for variation in lighting alignment, but it's more useful than the
previous attempt which was based on a misunderstanding of how environment
mapping worked.
1. Do not stop scanning STG files after OBJECT_BASE is found.
2. Load OBJECT_BASE only once.
3. Load OBJECT only when no OBJECT_BASE has been found or when
OBJECT_BASE was found in the same file (probably should be only the
latter, if we constrain OBJECT_BASE always to come first).
4. Always load OBJECT_STATIC and OBJECT_SHARED.
from the rest of the runway lighting. VASI/PAPI lights are generally
always on. Also, the red/white VASI coloring has never worked right.
This is also a step towards fixing that problem.
This patch is there to correct a problem that prevent to load static objects when specifying a relative fg-root or a different, relative, fg-scenery. It appears that there is a mix between fg-root, fg-scenery and PLIB's model-dir.
It has been reported on the list that users are not able to see the buildings, especially those running the win32 builds because they run 'runfgfs.bat' that set FG_ROOT=./DATA.
I decided not to use model-dir because it just add confusion and to build a valid path earlier.
search when loading scenery tiles. (I am not set on using ";" as the
delimiter because it is a command separator in unix, but ":" is a critical
part of the windows file naming scheme (c:\foo\bar) so that is even worse.)
Example:
--fg-scenery=/stage/fgfs04/curt/Scenery-0.9.1/Scenery;/stage/helio1/curt/Scenery
-0.7.9
