This makes it possible to make units heavier, which both push more & get
pushed less by other units.
In particular, the diff does it for siege units & elephants.
This improves movement for these units in crowd situation, since they
will now basically not move when other regular units push into them.
Supported By: asterix, marder
Refs #6127
Differential Revision: https://code.wildfiregames.com/D4452
This was SVN commit r26275.
The main change is the introduction of a 'pushing pressure' counter on
units. This counter increases when units get pushed around, and
decreases over time. In essence, units under high pressure move slower &
are harder to push around.
The major effect is that units can now get bogged down when very dense
groups start colliding. This makes movement more realistic, makes unit
movement more 'chokepointy', and generally improves the mathematical
soundness of the system (lower values are easier to handle for our 200ms
turns).
Other changes:
- The logic to detect units crossing each other's path has been
reworked. Units that run towards each other should not more obviously
avoid each other.
- New parameters: 'Spread' is a measure of how strong the pushing effect
is based on distance. With the current settings, static-pushing is
rather 'on/off', whereas moving-pushing is more gradual (and thus the
max influence distance was increased when moving).
- Default values have been tweaked for lower overlap.
- Units only looked at other units within their grid region. This led to
overlap near grid-borders. Units now look at neighboring grid elements,
which largely removes this issue. While this may be slower, the
performance of pushing was largely negligible before, so it is unlikely
to become a main cause of lag (and overlap was generally disliked by
players).
- Units no longer orient in the direction of pushing, but instead keep
facing their target. This can look slightly odd under very heavy pushing
forces, but vastly improves behaviour of very slow units such as rams
(since they spend much less time turning around). As a side-effect,
clean up angle code following acc780bcbb .
Engine changes:
- Add a debug rendering mode at compile-time to help understand what is
happening.
- Make it possible to constexpr initialise fractional fixed numbers by
using FromFraction
The 'pressure' change was inspired by alre's suggestion at
https://wildfiregames.com/forum/topic/56436-for-a-better-unit-movement/#comment-461987
Refs #6127
Differential Revision: https://code.wildfiregames.com/D4439
This was SVN commit r26245.
Following 40cbde1925, the minimum pushing force is 0.2. This also
happens to be the maximum pushing force any pair of units can exert on
each other, so they can freely overlap instead of being pushed.
This tweaks settings slightly to fix that problem.
Reported by: marder
Differential Revision: https://code.wildfiregames.com/D4129
This was SVN commit r25748.
This overall decreases the deathball effect from units walking to each
other a bit.
- Fix formations - this cleans up a UnitMotion hack for formations,
making it possible to increase pushing ranges without breaking closely
knit formations like testudo.
- Make MINIMAL_PUSHING and the MOVE_EXTENSION configurable, and add a
STATIC_EXTENSION as well.
- Increase the pushing range significantly, making units sparser.
Differential Revision: https://code.wildfiregames.com/D4098
This was SVN commit r25708.
Reduces the 'clumpiness' of units, particularly when ordered to move to
a single point. The minimum pushing force was increased to compensate.
Differential Revision: https://code.wildfiregames.com/D3978
This was SVN commit r25479.
This implements a form of crowd movement that I've generally called
'unit pushing' in the last few years.
Essentially, any two units will push each other away when they're too
close. This makes it possible to ignore unit-unit obstructions, and thus
makes movement much smoother in crowds.
This first iteration of this system only allows pushing between idle
units and between moving units (i.e. a moving unit does not affect an
idle one).
This is because the unitMotion logic to detect it is stuck & needs to
use the pathfinders starts breaking: units can fail to move because they
are pushed away from their intended movement, and the current logic
fails to handle this gracefully.
Thankfully, the most value of this patch in terms of player experience
is found in the improvements to group movements and shuttling.
Other impacts:
- As the short pathfinder is called less often, we can increase the
starting search range & reduce the # of max turns, both improving
collision recovery.
- The performance of idle units is slightly worsened, as they must be
checked for idle-idle collisions. If needed a 'sleeping' system, as used
in physics engine, could be implemented.
- In general, however, expect slight performance improvements, as fewer
short paths are computed.
- Gathering efficiency should increase slightly, since shuttling times
are likely reduced slightly.
- As a sanity change to improve some edge cases (units that say they're
moving, i.e. pushable, but don't actually move), the 'going straight'
logic is turned off if a short path has been computed. This requires a
few cascading changes to work correctly.
Technical notes:
- To reduce the cost of the n^2 comparisons that pushing requires, units
are only compared within a small square on a grid which is lazily
reconstructed each turn. The overhead seems rather small, and this is
much simpler than keeping an up-to-date grid.
- The design is intended to be parallelisable if needed someday.
- The pathfinder's CheckMovement ignores moving units in UnitMotion, as
that is now the spec. Idle units are not ignored, which is required for
the 'collision' detection to work correctly (see above).
Refs #3442 (not fixed - idle units are not pushed by moving units).
Fixes#5084 (the overlap can still happen, but units will push each
other away).
Differential Revision: https://code.wildfiregames.com/D1490
This was SVN commit r25182.
Following bae258f9a1, all units moved, then all messages were sent. This
could result in units overlapping, which cannot be resolved without unit
pushing. Fixing this makes for a fairer comparison with the pushing
diff, so it seems worthwhile.
Differential Revision: https://code.wildfiregames.com/D3746
This was SVN commit r25126.
bae258f9a1 implemented CCmpUnitMotionManager, which handles motion for
CCmpUnitMotion (as distinct from ICmpUnitMotion, the interface).
The tight coupling between these two components was awkward at the
interface level, leaking underlying implementation details.
This diff makes CmpUnitMotionManager explicitly manage CmpUnitMotion,
instead of any implementation of ICmpUnitMotion, and moves files around
as requir
ed.
This:
- Makes it impossible to accidentally try to have the wrong
IID_UnitMotion managed by the UnitMotionManager.
- Allows devirtualising the calls from the manager to UnitMotion itself
(and inlining, as they are compiled in the same TU).
- Cleans up the manager interface - MotionState is now part of
CCmpUnitMotionManager.
- Cleans up ICmpUnitMotion interface - no need to provide a private
interface for the manager.
Differential Revision: https://code.wildfiregames.com/D3732
This was SVN commit r25125.
