Remove rotors from helicopter?

[AndyLandy]

Hello,

I've created a GRF file with some helicopters in, but I'd like to make one a VTOL without any rotor blades. Is there a simple way of disabling the addition of rotor blades to a chopper? I've had a look through the documentation for Action3 and it says it's possible, but I couldn't find any examples.

As ever, all advice gratefully received!

[Transportman]

Doesn't it work when you provide a sprite with only transparent blue?

[mart3p]

Doesn't it work when you provide a sprite with only transparent blue?

You do have to provide a transparent blue sprite but you also need an action 3 livery override to set that as the rotor sprite. The livery override must immediately follow the helicopter's action 3.

Something like this...

Code: Select all

//Graphics for vehicle
  0 * 0	 03 03 01 // n-id
		26 // vehicle ID
		00 
		02 00 // sprites for helicopter

//Rotor override
  0 * 0	 03 03 81 // n-id - note, bit 7 set
		26 //  vehicle ID
		00 
		03 00 // sprites for rotor

[michael blunck]

[...]you also need an action 3 livery override to set that as the rotor sprite. The livery override must immediately follow the helicopter's action 3.

IIRC, this is an obsolete restriction which had been lifted as early as 2.0.1 alpha 41 (TTDPatch, that is).

regards
Michael

[mart3p]

IIRC, this is an obsolete restriction which had been lifted as early as 2.0.1 alpha 41 (TTDPatch, that is).

Yes, it's a very long time since I studied the OpenTTD helicopter rotor code.

[AndyLandy]

OK, got it working, thanks!

Took me a while to get my head round Action2/Action3 interactions, particularly since I'm using an Action2 callback to add some text into the purchase vehicle dialog. Forgot that it still needs its own unique set-id, which I was overwriting with the new rotors. Oops.

For the "invisible" sprites, I simply copied the original sprites and blanked them out as entirely blue. Do I need four blue sprites, or can (and should) I just use a single blue sprite for all variations on a rotor? (On the other hand, it makes it nice and easy if I want to add some custom rotor designs later!)

Anyways, thanks again for all your help and input so far.

[Transportman]

You can use one single sprite.

[michael blunck]

You can use one single sprite.

A single blue pixel would be sufficient.

regards
Michael