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.
the tile cache it's ssg elements are disconnected from the main ssg scene
graph, and then the tile is thrown on the end of a delete queue. The
tilemgr->update() routine runs every frame. It looks at this queue and if
it is non-empty, it incrementally frees the compents of the first tile
on the queue. When the tile is completely free it is removed from the queue.
The amount of time to free the memory for even a single tile can be quite
substantial, especially with the increased overhead of dynamic/random
ground objects. This change allows the system to spread the work of freeing
tile memory out over many frames so you don't get a noticable single frame
hit or stutter.
the triangles containing the objects were out of the view Frustum,
they were never traversed by ssg (and thus, never culled). Now, every
200 frames, do a pass through the whole scene graph with cull-testing
disabled and without drawing anything; that will allow random-objects
to be collected incrementally.
failed on /sim/time/gmt-string because the raw value contains an embedded
space. Now I use a regex instead of a plain split(). I also removed the
view_next and view_prev functions. These will have to be replaced with
command properties.
I've also added a FGFSDemo.py script which is a python version of David's java program.
-----------------------------------------------
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.
