how to scale afp/afpd models
 

Hi
how do you scale models up and down for afp and afpd models,
Thanks

RE: how to scale afp/afpd models
 

Hi,

you can scale the geometry file .OBJ with a tool of Rainer Stein.

http://home.arcor.de/rainerstein/afp/index.htm
Check for Zoom Tool.

BUT!!!
This only modifies the graphics file, all the parameters in the TMD have to be changed manually.
This means especially adjusting the JointValues and the root-coordinates to the new size.

Example:
cd JointFuselageRightwing/
...
R = tmvector4r( -1.0665, -0.5003, 0.6568, 1 )


cd Leftwing/
...
RootR = tmvector4f( -1.0263, 0.4834, 0.6399, 1.0000 )


Also, after scaling the model you will change the weight of it.
So you also have to set the forces and dampers for the Joints.

Example:
cd JointFuselageLeftGear/
Kn = 1000
Dn = 20
Dv = 5
Body0 = ../Fuselage/
Body1 = ../LeftGear/
Kf = 10000
Df = 9
Ktx = 1000
Dtx = 1
Kty = 1000
Dty = 1
Ktz = 1000
Dtz = 1
MaxForce = 0
MaxTorque = 0
Rigid = 0


What I want to say, it's not just done by an automatic scaling. You have to be familiar with TMD.
See workshops at my site.

Regards
Rodeo
www.rodeo.onlinehome.de

RE: how to scale afp/afpd models
 

Please clarify. If I use Zoom AFP to rescale the vertex data in the .obj file is that enough to see a difference in the sim? (regardless of whether the physics is updated in the tmd)

Because I'm trying to rescale the cap232-rcsim obj file. And even though I can "shrink" the data in the .obj file by 50% using zoomafp it still looks exactly the same when I load it up in AFPD. Do I have to alter data in the tmd file before the airplane will appear different?

Clark

RE: how to scale afp/afpd models
 

OK, it appears that another file, cap232-rcsim.tgo is interfering with the rescaling attempt. If I remove this file, my rescaled .obj file actually seems to work. I see a 50% scaled model in the sim. Only problem is, the sim runs a 1 frame per 5 seconds!!

So what is this tgo file for? It is preventing zoom AFP from working...

Clark

RE: how to scale afp/afpd models
 

Hi,

the geometry file for AFP was an .OBJ file.
The geometry file for AFPD is a .TGO file.

This means:
1. We can only zoom models from AFP, not AFPD.
2. You have to remove a .TGO file from the aircraft folder, because it will load first.

You should modify the TMD before loading the aircraft in AFPD.
If you rescaled the model to 50%, rescale all the joint coordinates by the same value.


Example:

cd JointFuselageLeftStabilizer/
...
R = tmvector4r( -0.8580, 0.0000, 0.0528, 1 )

Scale the first 3 values, they mean the x,y,z distance from center.


BRG
Rodeo
www.rodeo.onlinehome.de

RE: how to scale afp/afpd models
 

surely thats re-writing the whole TMD folder? thats big work isnt it??????

Thanks
Ian

RE: how to scale afp/afpd models
 

Thanks

Yeah, I think I'll write a utility to do all of this in one swoop.
Might as well update the masses, inertia matrices, and joint strengths at the same time too.

Clark

RE: how to scale afp/afpd models
 

OK, I've got my utility to the point where it rescales the vertex data in the .obj file, removes any redundant .tgo file, rescales the "R" vectors and "RootR" vectors in the .tmd file, every constant in the tmd file that looks to be mass or force related (eg, kn, dn, ktx, etc), wing section chords and areas, etc.

Haven't touched the inertia matrix yet. I don't know if it scaled by mass in the file or if mass is combined at run time.

The aircraft appears rescaled properly, but the frame rate is still <1 fps. [:o]

Anyone know what I'm missing?

Clark