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Author SHA1 Message Date
ehofman
26e6b0edcb Vivian Meazza:
I have added <Cd> and <weight> to the input parameters in the submodels.xml
script. Raw data may be used, thus avoiding the need to guestimate <eda>.
Eda remains, but should now be used to enter the proper cross-sectional
area.
2004-09-22 08:47:05 +00:00
ehofman
6d76e9da80 Vivian Meazza:
I had to reverse a number of signs to get it right. I took the opportunity
to add roll to the submodel so that droptanks will come off with the right
orientation. I have neither added the rotational speed to the submodel, nor
yaw, so if you release droptanks with  significant roll rate or yaw angle on
the aircraft the submodel will not be quite right. Straight and level, or
nearly so, is fine.
2004-09-17 16:32:58 +00:00
ehofman
2f581faf3e Vivan Meazza:
The maths, so far, is now correct. Roll and pitch are now both in the
correct sense. The aircraft velocity is added correctly to the
submodel velocity, and the submodel is now visible when instantiated.

However, the velocity is measured at the aircraft centre. To be totally
correct we ought to take into account the aircraft's rotational
velocity. We have pitch rate and roll rate available, but not yaw rate
(small anyway).
2004-09-14 08:27:55 +00:00
ehofman
d712d18acb David Culp:
Here are some things I've added to the submodel code.

First, I added a first_time value that is true when the trigger is pressed and
false when the trigger is released.  The true value is also made false after
the first pass through release().  Release() then uses this to force the
first dt (per salvo) to be zero.  I was hoping this would make the submodel
appear closer to the airplane, but I don't notice a difference with the
tracers.  In a prior test I found that the first dt is about 2.5 times larger
than subsequent ones.  Maybe this will be effective with slower submodels,
like smoke, contrails, etc.

Secondly, I updated the IC.elevation and IC.azimuth calcs to correctly add in
the yaw and pitch offsets, corrected for bank angle.  Actually this is still
an estimation.  A proper calculation will sum the submodels vector with the
airplane's vector.  Until that's done only models which are fired forward
will have proper IC.
2004-09-09 08:40:08 +00:00
ehofman
9e72a38165 Rearrange ID related code. The (this) pointer is now the unique ID of the AIModel which fixes a number of problems along the way. 2004-09-08 13:21:40 +00:00
ehofman
0d576e1925 Vivian Meazza:
Testing revealed that the code was not reading y-offset - a
typo in the original code, and roll was in the wrong sense. All readily
fixable, and it now works.
2004-09-07 19:10:10 +00:00
ehofman
d158c8168d Make use of a pointer to a structure to pass multiple parameters around. 2004-09-07 09:53:23 +00:00
ehofman
fed4a2c25a Vivian Meazza:
I've added another parameter to the submodel - wind.

It's activated by the entry <wind>true</wind> in the ../submodel.xml file.
If true, the submodel is affected by the local wind, otherwise not. The
parameter defaults to false. This is useful for exhausts and smoke, and
possibly all objects.
2004-09-05 09:45:34 +00:00
ehofman
30f3bd5096 Add the missing buoyancy patch. 2004-09-01 21:05:04 +00:00
ehofman
d2d27f2d76 Tie the count into the property tree instead of using snprintf every frame. Add the life-timer to the property tree under sim/time/elapsed-sec for AI object animation (blending and/or scaling). 2004-08-30 11:13:29 +00:00
ehofman
fdab44652e David Culp: This is n idea from Vivian, it allows setting the count to a negative number which will give unlimited submodels (as long as the trigger is true). This is useful for contrails. 2004-08-30 09:15:04 +00:00
ehofman
af284e4bb9 David Culp: Here are small changes that allow one to set a life-span for submodels. 2004-08-30 09:11:59 +00:00
ehofman
cfc05f5f0d David Culp:
Silly me.  I was starting the timer at zero, so the first tracer didn't fly
until 0.25 seconds after pulling the trigger.  Now the timer starts at the
same value as "delay", so the first round comes out immediately.

Also, I've added an optional configuration attribute that allows you to change
the ballistics of the submodel.  This allows parachutes, or anything else
that has ballistics different from a bullet.  The attribute is called "eda",
which is the equivalent drag area.  Default value is 0.007, which gives the
same ballistics as the current tracers.  Increasing this value gives more
drag.  A value of 2.0 looks good for a parachute.


math stuff
########################################################################
The deceleration of the ballictic object is now given by:

[ (rho) (Cd) ] / [ (1/2) (m) ] * A * (V * V)

where rho is sea-level air density, and Cd and m are fixed, bullet-like
values. So the calculation is:

0.0116918 * A * (V * V)

The value "A" is what I'm calling the "eda" (equivalent drag area).
########################################################################


A parachute model will have to be built so that the parachutist's feet
are in the forward x-direction.
Here is the submodel.xml config I use for "parachutes":

  <submodel>
    <name>flares</name>
    <model>Models/Geometry/flare.ac</model>
    <trigger>systems/submodels/submodel[0]/trigger</trigger>
    <speed>0.0</speed>
    <repeat>true</repeat>
    <delay>0.85</delay>
    <count>4</count>
    <x-offset>0.0</x-offset>
    <y-offset>0.0</y-offset>
    <z-offset>-4.0</z-offset>
    <yaw-offset>0.0</yaw-offset>
    <pitch-offset>0.0</pitch-offset>
    <eda>2.0</eda>
  </submodel>
2004-08-26 16:25:54 +00:00
ehofman
065d4d8da1 David Culp, Vivian Meazza:
Last night I sent these new files to Vivian to fix a problem he found.  Since
we can have more than one submodel we need more than one "count" property.
The new code creates a property systems/submodels/submodel[n]/count for each
submodel.  Vivian is using this count property for his sound.
2004-08-26 12:27:39 +00:00
ehofman
c4aa3fa661 David Culp:
Here is an update for the submodel system.  This will allow submodels to be
defined for any aircraft, and there are no default submodels.  To use this
submodel system you need to set up a binding (slight change in property name
from last one, but you can use any property name you like, as long as it
matches the name in the submodels.xml file, see below):

 <button n="0">
  <desc>Trigger</desc>
  <binding>
   <command>property-assign</command>
   <property>/systems/submodels/trigger</property>
   <value type="bool">true</value>
  </binding>
  <mod-up>
   <binding>
    <command>property-assign</command>
    <property>/systems/submodels/trigger</property>
    <value type="bool">false</value>
   </binding>
  </mod-up>
 </button>


Then in your *-set.xml file you need to define a path to the configuration
file (similar to the way the electrical system is now done):

<sim>
 ...
  <systems>
   <electrical>
    <path>Aircraft/Generic/generic-electrical.xml</path>
   </electrical>
   <submodels>
    <serviceable type="bool">true</serviceable>
    <path>Aircraft/FW190/submodels.xml</path>
   </submodels>
  </systems>
 ...
</sim>


Then you put the submodel configuration file in your aircraft's directory.
I've attached a file, submodels.xml, that can be used to define a gun that
works just like the former one did.


There are two things remaining to be done.  One is to change the function
SubmodelSystem::transform() to properly position the submodel.  This will
require some complicated matrix code that I might borrow from Yasim.
2004-08-26 08:38:43 +00:00
ehofman
83ca912de2 Fix another one of those mistakes. I really shouldn't mess with code from others (without looking at it closely) :-( 2004-08-23 17:40:46 +00:00
ehofman
c4c67480ff Fix a mistake and make it possible to activate the submodel subsystem again. 2004-08-23 17:33:36 +00:00
ehofman
be6936be80 Vivian Meazza:
Well here's some tracer stuff. If fiddled around with submodel.cxx. It now
does what it says - you need to put this:

<!-- trial gun system -->
    <systems>
      <submodel>
        <serviceable type="bool">true</serviceable>
        <amount type="int">120</amount>
      </submodel>
    </systems>

In the *-set.xml file NOT within <sim></sim>. Trouble is it still defaults
to serviceable=true, but it also defaults to amount=0. Unless this bit of
code is included it wont run, so other models can't fire inappropriate
tracer. Revised submodel.cxx file attached.

I've changed to a non-billboard solution. I tried to make the viewing angle
of the tracer less than 180 degs, but failed. Close enough I think. It's
still a bit big, but a reasonable compromise. .AC file attached.

I remain concerned about the tracer colour. In practice, red is better (and
it's what I am used to) but David seems set on white, and I don't want to
upset him. I'm going to adjust the texture a bit more tomorrow.
2004-08-23 17:22:55 +00:00
ehofman
7aa1cd9b5a I forgot a small patch. 2004-08-22 17:04:37 +00:00
ehofman
161912ea4c David Culp:
Right now the code is not very configurable, and there is only one submodel per airplane possible. It is implemented as an SGSubSystem, just like the electrics, vacuum, etc. systems.  To make it work you need to make a release binding like this (for my joystick trigger):

 <button n="0">
  <desc>Trigger</desc>
  <binding>
   <command>property-assign</command>
   <property>/systems/submodel/trigger</property>
   <value type="bool">true</value>
  </binding>
  <mod-up>
   <binding>
    <command>property-assign</command>
    <property>/systems/submodel/trigger</property>
    <value type="bool">false</value>
   </binding>
  </mod-up>
 </button>

Then, each airplane that uses the system should have something like this added to its *-set.xml file (note that this does *not* go within the <sim></sim> tags):

 <systems>
   <submodel>
    <serviceable type="bool">true</serviceable>
    <amount type="int">70</amount>
   </submodel>
 </systems>


Future improvements will include:
1)  more configurability, so the user can create multiple submodels, and can assign them different locations, and pitch and yaw adjustments, and nitial velocity.

2) sound?

3) a more accurate calculation of the submodels location at any pitch/roll/yaw.

4) a way to pre-load the model, so the AI code doesn't have to parse the model every time it creates an instance.

I think that's all of it.
2004-08-22 16:22:18 +00:00