Decorate help

[RichardDS90]

Need help, I wanna make a ripple laser projectile, like in Gradius, I'm having difficulty with it, I wanna make them grow, along with the radius and height properties, but I don't know anyway it can be done, another way is to spawn a larger version on the projectile from the smaller version, whilst retaining the angle, velocity, etc, any way this can be done?

[Tango]

I don't think there's any sort of convenient A_SetSize pointer or anything like that that actually affects height/radius, so I would guess your best bet is indeed making a few different versions of the projectile, each one larger than the previous, and they spawn each other sequentially. So if the projectiles' actor definitions were something like this:

Actor Ball1
  Height 1
  Radius 1
  ...

Actor Ball2
  Height 2
  Radius 2
  ...

Actor Ball3
  Height 3
  Radius 3
  ...

... then you could spawn them like this:

Actor Ball1
  ...
  Spawn:
    BAL1 A 4
    BAL1 B 4 A_SpawnItemEx("Ball2")
  ...

... and then repeat that for each subsequent actor, until it finally gets to the final, largest version. I would definitely look at A_SpawnItemEx and A_CustomMissile on the ZDoom wiki, as I can't recall which one exactly would be best suited (or work properly) in this situation. Does that make sense? D:

[RichardDS90]

That is exactly what I tried, whilst it DID work, the problem I have, however, is the projectile merely sits there, it doesn't move or anything.

[Blue Shadow]

A_SpawnItemEx allows to set the x, y and z velocities of the spawned object. You can transfer the velocities of the spawning object by passing velx, vely and velz to the function:

A_SpawnItemEx("Something", 0, 0, 0, velx, vely, velz)

For reference: http://zdoom.org/wiki/DECORATE_expressions#Variables

[RichardDS90]

Blue Shadow said:

A_SpawnItemEx allows to set the x, y and z velocities of the spawned object. You can transfer the velocities of the spawning object by passing velx, vely and velz to the function:

A_SpawnItemEx("Something", 0, 0, 0, velx, vely, velz)

For reference: http://zdoom.org/wiki/DECORATE_expressions#Variables

Would it have the same angle, pitch, velocity as the thing that spawned it?

[scifista42]

Yes, it would have the same angle, pitch and velocity. I'm not entirely certain if there wouldn't be other side effects, though (for example impact/collision-detection related ones), as projectiles are generally supposed to be fired by A_CustomMissile rather than A_SpawnItemEx.

[RichardDS90]

scifista42 said:

Yes, it would have the same angle, pitch and velocity. I'm not entirely certain if there wouldn't be other side effects, though (for example impact/collision-detection related ones), as projectiles are generally supposed to be fired by A_CustomMissile rather than A_SpawnItemEx.

Just tried them, it works for sure, but with a nasty side effect. The second projectile will go to one angle, never a different one.

[scifista42]

http://zdoom.org/wiki/A_SpawnItemEx

Try different flags. SXF_ABSOLUTEVELOCITY sounds like it might be what you need.

[Gez]

Salahmander2 said:

Would it have the same angle, pitch, velocity as the thing that spawned it?

http://zdoom.org/wiki/A_SpawnItemEx

Angle is transferred automatically, but you'll need SXF_TRANSFERPITCH for transferring pitch. For velocity, see what scifista said.

[scifista42]

Is it really needed to transfer pitch as the thing's property when you already transfer its Z velocity? It shouldn't affect the projectile's appearance or behavior, or does it?

[Gez]

It depends. A projectile's pitch might be used for various purposes (such as shooting subprojectiles with more A_SpawnItemEx calls and using pitch variable) and it can also be used for cosmetic reasons (e.g., when using a model, with INHERITACTORPITCH in MODELDEF).

If you're not planning on doing anything of the sort, the pitch value is pretty much pointless for anything that isn't a player pawn; but he did mention he wanted to transfer pitch, so whether there's a good reason for that or not, I mention how pitch can be transferred.

[RichardDS90]

scifista42 said:

http://zdoom.org/wiki/A_SpawnItemEx

Try different flags. SXF_ABSOLUTEVELOCITY sounds like it might be what you need.

OMG! That's the one! Thank you very much! :D