Parachutes - Requirements? (now with pic!)

[prefim]

Hi Guys,

I\'m struggling to put together what needs to be right for parachute making. I\'ve kind of figured out you have to have 4 things called.

base

cap

canopy

node_collider

but there seems to be issue with placing and orienting the canopy which behaves differently to the other layers (and other normal objects!)

any advice welcomes!

mat

EDIT: Heres my problem.

As you can see the chute is centred but above the base and cap. Also, the chute wants to be rotated over 90 degrees. The problem is the rotation point of the canopy is its middle (not the origin of the scene and not the end of the string.

Any ideas?

[Technical Ben]

Hi. Blender changes the axis of the files, so it\'s not your fault.

Blender changes the scene axis on export, but not the object axis. When the game loads the parachute model, it uses the scene axis for the parts. But for the chute, it checks the object axis, which Blender has not corrected. (At least as far as I can tell).

So, there are three ways to fix this. Rotate your entire model 90 degrees on the x axis. Go into the .collada file and edit the attributes in a text editor. Or do it the way I do and 'cheat'.

I make a new axis (Add: Empty) then rotate it 90 degrees on the x axis. Call this obj_canopy. Now go to your chute object, and change it\'s parent to the new axis you made. Rotate your parachute -90 degrees on the x axis. You should now have your chute facing the correct way in Blender, and when in game.

I\'ll try and add this to my tutorial ASAP.

[prefim]

Hi Ben,

I get what you are saying but I\'m not using blender, thats lightwave 10 in the screenshot. and I spit out OBJ files not DAE which for everything else in the game seem to work (see my tardis and orion releases) but for this the canopy object behaves differently to the other parts of the object.

From my images you can see the I have the chute the right way round in game (even if its off in lightwave) but it rotates around its centre not its tip so the string waggles back and forth (and i found out recently that if I turn the ship the chute does some very bizarre things!). its all to do with the object origin i know but I don\'t see how to change it with what I have.

Whats the cheat in blender BTW?

[Technical Ben]

Sorry, I missed that somehow. As said. In Blender I make a new 'empty object' or an empty axis. I rotate the axis - 90 degrees on the x direction. Then add the chute to the axis as a child (this should turn your cute around as well). Then I rotate the chute back (but keep the empty axis at - 90 degrees). This should force the program to rotate the axis properly.

The problem is Art programs use one set of co-ordinates and engineering programs use another. Guess what category games and programming come under? Yep, the opposite to art programs.

I think Z is front/back in blender/lightwave and in game Z is up/down. I\'m not too sure though...

[Killerhurtz]

Other way around, Ben. Z is front-back ingame (Y is up-down). Blender uses the Z-up convention, which means that Z is up-down and Y is front-back.

[prefim]

That also worked well. cheers again.

Not having used blender before it was a bit of a learning curve but figured out parenting (eventually) and was able to make a smaller parachute which worked well for another project (watch this space!)

[Technical Ben]

Other way around, Ben. Z is front-back ingame (Y is up-down). Blender uses the Z-up convention, which means that Z is up-down and Y is front-back.

Oops. Like I said, it confuses me. Thanks.

[Tiberion]

Okay, blender and me are not on the same page here, and I dunno what the deal is.

It took me a while to realize I needed to rotate the canopy object without applying the rotation to the mesh (which is what ben is decribing with the parent object) but as far as I can tell I have the objects set up properly now..

And it shows up properly in the VAB icon like all the other chutes.. but when it deploys, the canopy is pointing down below the capsule . Rotating it 180 doesn\'t even change it.

What is causing the parachute vector to be flipped?

[SmiteZero]

And this is one reason I don\'t model for KSP.

..Or for the glossy mags.

*boom ching*

[Tiberion]

So after a bit of wrangling, I finally got blender to comply.

The top part of the image is how things are setup with Transform Rotation (x axis, 90 degrees) for all objects.

For the base, cap and collider, this is important so that the parts appear correctly as 'Y up'

For the Canopy, this ONLY affects how the canopy appears on its selection preview/icon. You can rotate it 9 ways from sunday by transforming the object and it won\'t change the deployed vector of the canopy.

The lower image is how the meshes are rotated with object Transform Rotation zeroed out; note how the base, cap, and collider point to +Y but the canopy is pointing to -Y; I am not sure why its this way, but its the only way it worked; with it pointing +Y it deployed pointing down below the capsule.

So, there ya go.

[semininja]

Since this is the parachute thread, I might as well ask: the Hidra Camping Tent parachute doesn\'t seem to like appearing partially deployed. It acts right, but it doesn\'t ever do the \'streamer\' look; it just opens all the way, but with less drag. Does anyone know why that might be?