How do I randomly spawn objects on other objects?

It's pretty easy to spawn objects randomly inside the window.

However, I want to spawn objects only on the ground on various platforms (side scroller).

Should I place invisible boxes on various places that they can spawn in? How would I go about doing that?

Black are platforms and green is where I want to spawn enemies:

https://www.dropbox.com/s/r15woy48zsrih2t/Untitled-1.jpg?dl=0

The image isn't displayed.

To "spawn" sprites like the way you describe, I like to use this method.

I create a square sprite that is invisible or covered by the sprite it spawned by "setting the position to object" and spawn an enemy or a bonus. I use that so you can set a random time or a random object to spawn via a global variable.

The "difficulty" would be to set a specific mouvement from your sprite. But maybe with the photo it will be clearer.

Try this link:

https://www.dropbox.com/s/r15woy48zsrih ... 1.jpg?dl=0

figured it out. i have an invisible object (spawnobj) and invisible spawnmarker. i have the spawn object move every second at random locations. when it finally moves over the spawn marker, it spawns the enemy.

I use that line:

Let say you have a spawner and multiple enemies. Add a variable to those enemies and pick a value for them, I called it Enemychoice here.

It's just in order to make your spawner choose randomly between multiple ennemies.

{_System// Every random(X1,X2) seconds---------------------Spawner01// set Enemychoice to choose 1,2,3

{_Spawner01//Enemychoice=1--------------------------Spawner01// Spawn E1 on layerA(image point0)

_Spawner01//Enemychoice (different as(the symbol isn't on my keybord))0------------------------Spawner01//set Enemychoice to 0

_System//trigger once.

{_Spawner01//Enemychoice=2--------------------------Spawner01// Spawn E2 on layerA(image point0)

_Spawner01//Enemychoice (different as(the symbol isn't on my keybord)) 0------------------------Spawner01//set Enemychoice to 0

_System//trigger once.

{_Spawner01//Enemychoice=3--------------------------Spawner01// Spawn E3 on layerA(image point0)

_Spawner01//Enemychoice (different as(the symbol isn't on my keybord))0------------------------Spawner01//set Enemychoice to 0

_System//trigger once.

Thank you!