The jitter is most likely caused by the irregular frame rate and CPU clock dependent intervals. There's no easy way around that. I tried some fancy interpolation and all that -- to no avail.
The current chase view respects heading but ignores roll & pitch. And it follows heading without delay, which makes the viewer behave quite strange. This change makes the chase view feel more natural. You aren't fixed behind the plane, but follow all its movements with a delay.
Erik Hofman:
I've decided not to add the patch to preferences.xml in the base package because something feels funny with that. I think there needs to be some more discussion about it.
What is actually happening is the camera is pointing to the right place (try zooming in), but the camera is also travelling up and down with the nose and it should be staying more steady (in sync with the CG altitude).
Attached is a fix for this. There is still something a little funky going on with the camera, but this solves the biggest problem. You will note that I deleted an unecessary reference to scenery.hxx in the patch.
I split the FGModelPlacement code out into it's own set of source files.
I created two versions of the fgLoad3DModel() routine. One that is
unecumbered by a panelnode dependency and one that is. acmodel.cxx is
the only place that needs to load an aircraft with instrument panels.
model.[ch]xx are now pretty much free to move over into simgear.
loader.[ch]xx should be able to follow closely behind.
This will be a big step towards being able to move the material management
code over into simgear.
scene management code and organizing it within simgear. My strategy is
to identify the code I want to move, and break it's direct flightgear
dependencies. Then it will be free to move over into the simgear package.
- Moved some property specific code into simgear/props/
- Split out the condition code from fgfs/src/Main/fg_props and put it
in it's own source file in simgear/props/
- Created a scene subdirectory for scenery, model, and material property
related code.
- Moved location.[ch]xx into simgear/scene/model/
- The location and condition code had dependencies on flightgear's global
state (all the globals-> stuff, the flightgear property tree, etc.) SimGear
code can't depend on it so that data has to be passed as parameters to the
functions/methods/constructors.
- This need to pass data as function parameters had a dramatic cascading
effect throughout the FlightGear code.
04Feb. Actually been running since the beginning of January with these
patches. All changes work without crashing with the current base package cvs,
but there are some visual problems with the views (other than pilot view)
without changes to the base package.
As soon as you can build test and commit I can add in those base package
updates that will make it all work nicely. I will also go through all the 3D
Aircraft configs to make sure the change in the "pitch-offset" for cockpit
views (see below) are made to maintain current behavior.
Here are the files (changes listed below):
http://www.spiderbark.com/fgfs/viewerupdate.diffs.gzhttp://www.spiderbark.com/fgfs/viewerupdate.tar.gz
This is a small fix for what turned out to be a major bug. Ground elevation
was calculated incorrectly when distant from one of the view locations. This
resulted in several problems including bizarre gear trimming, mid air
"crashes" (as in thinking we hit the ground) and so on when close to or on the
ground.
Unfortunately it does require a second ssg traversal when in tower view
(only), but the increased load isn't all that noticable. For the time being
this really is the best solution. In a future update I will be eliminating
the unecessary per frame traversals for the static views (without having to
maintain multiple ssgRoots).
When we go to multiple FDM instances we will perhaps need to put the ssg
traversal and ground elevation queries for the FDMs into an event timer that
updates the FDMs ground elevation in a round robin fashion (maybe every 1/n
seconds where n is the number of FDM instances running).
This is a new improved patch for the previous tile manager fixes.
Rather than building dependencies between FGlocation or the viewer or fdm with
tilemgr what I ended up doing was linking the pieces together in the Mainloop
in main.cxx. You'll see what I mean...it's been commented fairly well. More
than likely we should move that chunk somewhere...just not sure where yet.
The changes seem clean now. As I get more ideas there could be some further
improvement in organizing the update in tilemgr. You'll note that I left an
override in there for the tilemgr::update() function to preserve earlier
functionality if someone needs it (e.g. usage independent of an fdm or
viewer), not to mention there are a few places in flightgear that call it
directly that have not been changed to the new interface (and may not need to be).
The code has been optimized to avoid duplicate traversals and seems to run
generally quite well. Note that there can be a short delay reloading tiles
that have been dropped from static views. We could call the tile scheduler on
a view switch, but it's not a big deal and at the moment I'd like to get this
in so people can try it and comment on it as it is.
Everything has been resycned with CVS tonight and I've included the
description submitted earlier (below).
Best,
Jim
Changes synced with CVS approx 20:30EDT 2002-05-09 (after this evenings updates).
Files:
http://www.spiderbark.com/fgfs/viewer-update-20020516.tar.gz
or
http://www.spiderbark.com/fgfs/viewer-update-20020516.diffs.gz
Description:
In a nutshell, these patches begin to take what was one value for ground
elevation and calculate ground elevation values seperately for the FDM and the
viewer (eye position). Several outstanding view related bugs have been fixed.
With the introduction of the new viewer code a lot of that Flight Gear code
broke related to use of a global variable called "scenery.cur_elev".
Therefore the ground_elevation and other associated items (like the current
tile bucket) is maintained per FDM instance and per View. Each of these has a
"point" or location that can be identified. See changes to FGLocation class
and main.cxx.
Most of the problems related to the new viewer in terms of sky, ground and
runway lights, and tower views are fixed.
There are four minor problems remaining. 1) The sun/moon spins when you pan
the "lookat" tower view only (view #3). 2) Under stress (esp. magic carpet
full speed with max visibility), there is a memory leak in the tile caching
that was not introduced with these changes. 3) I have not tested these
changes or made corrections to the ADA or External FDM interfaces. 4) The
change view function doesn't call the time/light update (not a problem unless
a tower is very far away).
Details:
FDM/flight.cxx, flight.hxx - FGInterface ties to FGAircraftModel so that it's
location data can be accessed for runway (ground elevation under aircraft)
elevation.
FDM/larsim.cxx, larcsim.hxx - gets runway elevation from FGInterface now.
Commented out function that is causing a namespace conflict, hasn't been
called with recent code anyway.
FDM/JSBSim/JSBSim.cxx, YASim/YASim.cxx - gets runway elevation from
FGInterface now.
Scenery/newcache.cxx, newcache.hxx - changed caching scheme to time based
(oldest tiles discard).
Scenery/tileentry.cxx, tileentry.hxx - added place to record time, changed
rendering to reference viewer altitude in order to fix a problem with ground
and runway lights.
Scenery/tilemgr.cxx, tilemgr.hxx - Modified update() to accept values for
multiple locations. Refresh function added in order to periodically make
the tiles current for a non-moving view (like a tower).
Main/fg_init.cxx - register event for making tiles current in a non-moving
view (like a tower).
Main/location.hxx - added support for current ground elevation data.
Main/main.cxx - added second tilemgr call for fdm, fixed places where viewer
position data was required for correct sky rendering.
Main/options.cxx - fixed segfault reported by Curtis when using --view-offset
command line parameter.
Main/viewer.cxx, viewer.hxx - removed fudging of view position. Fixed numerous
bugs that were causing eye and target values to get mixed up.
- changed FGSubsystem::update(int) to
FGSubsystem::update(delta_time_sec); the argument is now delta time
in seconds rather than milliseconds
- added FGSubsystem::suspend(), FGSubsystem::suspend(bool),
FGSubsystem::resume(), and FGSubsystem::is_suspended(), all with
default implementations; is_suspended takes account of the master
freeze as well as the subsystem's individual suspended state
- the FDMs now use the delta time argument the same as the rest of
FlightGear; formerly, main.cxx made a special case and passed a
multiloop argument
- FDMs now calculate multiloop internally instead of relying on
main.cxx
There are probably some problems -- I've done basic testing with the
major FDMs and subsystems, but we'll probably need a few weeks to
sniff out bugs.
These are the updates for the View manager properties. Removed the last of
items (within the viewer/viewmgr) hard coded to view number. Added support
for per view configuration of ground level nearplane value. Tower views look
very nice with little or no z-buffer problem in the models. Pilot offset
dialog can be used to move eye in all views.
Synced to CVS 19:36 EDT 2002-04-10 (after this evenings JSMsim and Base
package updates).
Description:
Added FGLocation class which is new home for calculating matrix rotations.
Viewer can now be configured to access rotations created by the model rather
than repeating the same calculations again.
Changed model initialization for the time being so that its location data is
available for the viewer (currently required by other subsystems). At some
point we can move this back to fg_init along with the viewer initialization.
Seperated the update from the draw function in the model code. The viewer
code needs the same matrix data, and moving the update portion at this time
does not increase the number of matrix math iterations.
Moved the model draw so that it always appears "in front" of lights and clouds.
Reogranized viewer update routine for using the FGLocation class and
simplified some more tasks. The routine is fairly easy to follow now, with
the steps ordered and spelled out in comments.
Viewmgr only updates the current (visible) view now, with the exception of an
old reference to "chase view" that will be corrected in forthcoming changes.
Also will be doing some work on the viewmgr outputs.
Model is now clears the z-buffer in all modes. This will be changed with the
next viewmgr update. The only side effect is that models always disappear
when over 5km distant from the eye point (can't really see them anyway:-)).
Other than a flag to indicate "internal" view I don't anticipate the
configuration interface for viewmgr/views will be changed a lot for now. It
is close to done. The next viewmgr update will however rework the outputs so
may change location.
This code will run with the previous version of preferences.xml, but will run
faster with the newer version. I am attaching a preferences.xml that should
not be commited before the code. All the changes are in the /sim/view section
and should show a simpler view configuration that references model locations.
Note that I've added a 2nd tower view in "lookfrom" mode for illustration
purposes. You can look around using the mouse. You may want to remove that or
comment it out.
Minor patches to initial tower view code. Added calculation for "tower" at
any airport, placed a couple fractions of a degree off the center. Moved the
farplane from 100m to 5km so that "lookfrom" mode can see the model. 5km is
still in a reasonable range for a depth buffer. Note that looking at a model
anything but a small distance will cause some problems on older cards.
Temporarily changed viewer to always report elevation/lon/lat of the aircraft
in order to avoid a problem with the ground trim getting recalculated when
tower and aircraft are on different tiles.
Tower View and viewer config is in place. Note that the interface is
still in a state of flux. A couple of the config items (namely the
offsets) are still using the old settings. The tower is hard coded
into the base package for a position off the starting runway at KSFO
and is probably not in the right place for there even. Looks pretty
cool though! Tower View is the third view. If you aren't at KSFO
you'll just see blank space in view 3. It's looking through the earth or
something like that :-). Important note: zoom in with a few
hits of the "x" key to see the plane better in tower view.
The matrix doesn't define some cells, which are actually used
in the multiplication. That makes the result unpredictable.
I have no idea if 0.0 is the correct value for these, but
garbage is hardly the correct value either. Should some of them
be set to 1.0?
Think my brain is getting clogged with matrices :-). Well I've got the funky
orientation offset bug out of the model code. In the process the model.cxx
got optimized a bit. At some point we'll need to liberate model.cxx from the
viewer class, but it is no longer hard coded to access the "pilot view" to
get it's data. Instead it uses whatever the "current" view happens to be. I
may try and do that final bit of having models rotate independant of the view
tomorrow night, or start right in on the viewmgr and get a tower view up and
running. You guys have any preference? My brother's family is coming to
visit for a few days so what I don't get done tomorrow night probably won't
get done until after the weekend.
Fix FGViewer::update so that pitch offset and goal pitch offset work
together nicely (the offset was snapping to 90/-90 when only one of
the two was changed).
Viewer improvements from Jim Wilson:
These files get the 3d cockpit working and fix a few issues in the viewer
code.
XYZ offsets are now defined as follows: X -left/right+ (along wing axis), Y
-up/down+ perpendicular to the aircraft, Z is -in/out+ the aircraft's body axis.
I've also done some cleaning up of unused and mostly unusable interfaces,
added commentary to the *.hxx, combined together some duplicate code and
eliminated a couple unecessary operations. I also moved what was left of the
"protected" zone to "private" since we aren't subclassing this anymore.
Description:
This update includes the new viewer interface as proposed by David M. and
a first pass at cleaning up the viewer/view manager code by Jim W.
Note that I have dropped Main/viewer_lookat.?xx and Main/viewer_rph.?xx and
modified the Makefile.am accordingly.
Detail of work:
Overall:
The code reads a little easier. There are still some unnecessary bits in
there and I'd like to supplement the comments in the viewer.hxx with a tiny
bit on each interface group and what the groupings mean (similar but briefer
than what you emailed me the other day). I tried not to mess up the style,
but there is an occasional inconsistency. In general I wouldn't call it done
(especially since there's no tower yet! :)), but I'd like to get this out
there so others can comment, and test.
In Viewer:
The interface as you suggested has been implemented. Basically everything
seems to work as it did visually. There is no difference that I can see in
performance, although some things might be a tiny bit faster.
I've merged the lookat and rph (pilot view) code into the recalc for the
viewer. There is still some redundancy between the two, but a lot has been
removed. In some cases I've taken some code that we'd likely want to inline
anyway and left it in there in duplicate. You'll see that the code for both
looks a little cleaner. I need to take a closer look at the rotations in
particular. I've cleaned up a little there, but I suspect more can be done
to streamline this.
The external declaration to the Quat_mat in mouse.cxx has been removed. IMHO
the quat doesn't serve any intrinsic purpose in mouse.cxx, but I'm not about
to rip it out. It would seem that there more conventional ways to get
spherical data that are just as fast. In any case all the viewer was pulling
from the quat matrix was the pitch value so I modified mouse.cxx to output to
our pitchOffset input and that works fine.
I've changed the native values to degrees from radians where appropriate.
This required a conversion from degrees to radians in a couple modules that
access the interface. Perhaps we should add interface calls that do the
conversion, e.g. a getHeadingOffset_rad() to go along with the
getHeadingOffset_deg().
On the view_offset (now headingOffset) thing there are two entry points
because of the ability to instantly switch views or to scroll to a new view
angle (by hitting the numeric keys for example). This leaves an anomaly in
the interface which should be resolved by adding "goal" settings to the
interface, e.g. a setGoalHeadingOffset_deg(), setGoalPitchOffset_deg(), etc.
Other than these two issues, the next step here will be to look at some
further optimizations, and to write support code for a tower view. That
should be fairly simple at this point. I was considering creating a
"simulated tower view" or "pedestrian view" that defaulted to a position off
to the right of whereever the plane is at the moment you switch to the tower
view. This could be a fall back when we don't have an actual tower location
at hand (as would be the case with rural airports).
ViewManager:
Basically all I did here was neaten things up by ripping out excess crap and
made it compatible as is with the new interface.
The result is that viewmanager is now ready to be developed. The two
preexisting views are still hardcoded into the view manager. The next step
would be to design configuration xml (eg /sim/view[x]/config/blahblah) that
could be used to set up as many views as we want. If we want to take the easy
way out, we might want to insist that view[0] be a pilot-view and have
viewmanager check for that.
fixed this when I made the mistake the first time.
The view code wasn't properly handling the transition across tile
boundaries so we'd get a 'flash' of the scene wrongly transformed for
one frame at every tile boundary crossing. This is what
scenery.get_next_center() is for.
created a new class, FGViewPoint (declared in viewer.hxx) that holds a
single position in FlightGear coordinates, and have used it to factor
a lot of the common code out of viewer_lookat.cxx and viewer_rph.cxx.
I don't know whether this new class will stay or not; it might just be
a temporary step, or it might end up taking over much of the current
viewer functionality. It would be a bad idea to code against it right
now.
was some confusion between degrees and radians which would lead to a huge
goal_view_offset value. The display would sit and spin for a *long* time
trying to wind it's way up to this large value.
max(width, height) by default (easily changeable) rather than just width.
(src/GUI/gui.cxx, src/Main/main.cxx, src/Main/viewer.cxx, src/Main/viewer.hxx)
1. Enable auto-configure on more versions of auto tools. (configure.in)
2. Warnings from auto-configure tools. (src/Time/Makefile.am)
3. Typo: "the it's" -> "its". (docs-mini/README.Joystick)
4. Remove definition of FGViewer::update() that now is (or can be) pure
virtual\
. (src/Main/viewer.cxx)
5. Preferred form of function name according to comments in plib:
"not_working"\
-> "notWorking". (src/Sound/soundmgr.hxx)
(i.e. multiloop). Most subsystems currently ignore the parameter, but
eventually, it will allow all subsystems to update by time rather than
by framerate.
derive specific viewer classes from it. Here's what I currently have in mind:
FGViewer
|
|-> FGViewerPRH (current system with orientation specified in
| LaRCsim Euler angle convention)
|
|-> FGViewerLookAt Feed in a position, view direction, and up vector
|
|-> FGViewerHPR (similar to PRH, but using ssg hpr euler angle
| convention)
|-> others?
