maintianed or upgraded in a *long* time so it didn't support many new
features like the runway lighting. If anyone was using it for anything,
it should not be a huge amount of work to switch to the binary format.
SimGear includes a reader and writer for the binary format.
are now working. A runway light is defined by a point and a direction. The
point and direction are combined with the local up vector to create a small
triangle orthogonal to the direction. The two ficticous corners of the
triangle are given an alpha value of zero, the orignal corner is given an
alpha of one. The triangle is drawn in glPolygonMode(GL_FRONT, GL_POINT)
mode which means only the corner points are drawn, and since two have alpha=0
only the original point is drawn. This is a long way to go to draw a point,
but it ensures that the point is only visible within 90 degrees of the light
direction, behind the light it is not visible. This is still a long way
to get to drawing a point, but we use an environement map, with the direction
vector as the normal to mimic a light that is brightest when viewed head
on and dimmest when viewed perpendicularly or disappears when viewed from
behind.
- warning, there is a bug in how the current runway light direction vector
is calculated which will adversely effect runway lighting. The airports
should be regenerated in order to fix this problem.
Here are some changes that gave me a significant frame rate increase of about 10 fps with random objects disabled. The interesting thing is that these changes aren't in the main loop but are in tile loader. My guess is that I've reduced the memory footprint just enough to reduce CPU cache misses, though I have no hard evidence of this.
Initially I modified all SGBinObject member functions to pass/return by reference instead of by-value. This gives little or no speed up but allows for some optimizations in fgBinObjLoad(). It is these changes that reduce the number of memory allocations. Needless copying of vectors, and vectors of vectors, can be very memory intensive, especially if they are large.
Anyway I would be interested to see if you get similar results. I would emphasize that the frame rate increase only occurs with random objects disabled. I lose about 10-15 fps on my GF2MX 32MB with random objects, probably a fill-rate limitation or texture memory thing.
name "random-objects".
Put the random objects for each tile inside a top-level
ssgRangeSelector with a maximum range of 20km. This saves a lot of
range tests for distant tiles, and gives about a 10% framerate boost
on my card at 1000ft AGL (possibly more on faster cards).
instead, use a separate dummy bounding sphere for each triangle and
each tile, with the actual bounds, to make sure that objects are
always added when they should be in sight.
-----------------------------------------------
Fixed a segfault on exit.
Changed the radius of the dummy bounding sphere from 10m to 1000m to
ensure that FOV culling doesn't leave anything out.
Allow an object to have more than one variant model, which will be
chosen randomly. Simply repeat the <path>...</path> property.
Removed the <billboard> property and replaced it with <heading-type>,
which can be set to "fixed" (leave the model oriented as it is),
"random" (give the model a random heading between 0 and 359 deg), or
"billboard" (always turn the model to face the camera). The default
is "fixed". Models look much better when they are not all facing the
same direction.
Allow the user to group models with the same visual range, so that
there can be *many* fewer nodes in the scene graph when the models are
not visible. This causes an XML-format change, so that instead of
<object>
<range-m>...</range-m>
...
</object>
<object>
<range-m>...</range-m>
...
</object>
...
we now have
<object-group>
<range-m>...</range-m>
<object>
...
</object>
<object>
...
</object>
...
</object-group>
Every object in a group can still have its own model(s), coverage, and
heading-type, but they all share the same range selector.
This change should already help users with tight memory constraints,
but it will matter much more when we add more object types -- for
example, we can now add dozens of different urban building types
without bloating the scene graph or slowing down the LOD tests for
tris that are out of range (i.e. most of them).
1. Only one copy of each object (and its texture) is stored in memory,
no matter how many materials use it.
2. Random objects are added to a triangle only when the objects are in
range, and they are deleted as soon as the objects are out of
range. That way, only a relatively small number of ssg nodes are
used at any one time.
This patch seems to eliminate freezes when tiles are freed. There are
occasional stutters at extremely high speeds (i.e. over 3,000kt), but
it seems smooth enough for normal aviation speeds.
- no extra nodes are created at all if the material has no random
objects defined
- the range selector is place correctly under the transformation
- there is only one range selector for each object type in each
triangle (experimental -- doesn't seem to make a difference in speed
or memory)
This patch removes Curt's patch that randomized ranges slightly, since
individual random objects no longer have their own range selectors.
It also leaves the object-group-range value unused, for now.
The first hunk might not be necessary, but the light_coverage property
was the only one that wasn't explicitly defaulted, which is unfair. ;-)
The second hunk adds the missing initialization to the init routine.
This is necessary, because (unlike the material entries from material.xml)
the generated light entries don't get the light coverage set. Yet
obj.cxx:795 reads this information out fot every leaf, although not needed
in the case of lights. Avoiding this isn't worth the trouble.
The last hunk sets the missing normal_index. The POINTS branch in
gen_leaf was always called with this int_list empty, which made the normals
handling use data garbage.
separate header file. This change will help integrate properties into
JSBSim.
Also, I (David Megginson) removed most of the SimGear include
statements from globals.hxx, reducing the amount of recompilation
every time SimGear changes. This required making minor changes to a
lot of files that were depending on the side-effects of the inclusions
in globals.hxx.
includes the ability to specify per vertex normals rather than depending
the normals list being the same as the vertices list. (Support for
previous binary file format scenery is maintained.)
