AngelScript: FreeForces (with a PartyBaloon demo mod) #3159
Conversation
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Not sure why, but game.getCurrentTruck().getInstanceId() doesn't work (trows an error) and i don't know what actor is the car to attach the baloon to. I don't think it was broken by this PR, it's months the entire angelscript panel (together with any getCurrentTruck() related command) don't work in dev builds. |
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@Miner34dev That's a quirk of our present reference-counting mechanism, sorry about that, I haven't yet found a way to fix it. You must do either |
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How does this affect performance? I have to apply a force to over 500 nodes, is it going to make me lag/crash? |
Tested it out, it's completely fine (at least if i add the force at the start and then leave it untouched.) |
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I'm having a problem with |
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@Miner34dev I tested your scenario and sure enough, the force isn't getting updated. UPDATE: fixed. My test script is below, I used it with 'Slalom Cone' load from Auriga map. To use the script, put it to directory 'Documents/My Games\Rigs of Rods\scripts'. |
FreeForces are global, persistent forces which act upon one node of one actor each. They exist separately from actors and their existing hook/tie/rope interactions. This means they do not interfere with actor N/B or any of the existing linking logic. They're intended for creating special physics effects which aren't supported otherwise, like making party baloons float. They're intentionally only accessible from scripts to maximize their flexibility and limit maintenance of the codebase.
Keep in mind that the physics simulation runs at 2khz (2000 steps per second), while scripts run in sync with FPS. That's why there's no option to add temporary/one-off force impulses from scripts - you are responsible for adding the persistent force, monitoring and adjusting it as needed, and then removing it when no longer necessary. You can create the forces as dummy and then change their type later as needed.
To manage FreeForces, you use `game.pushMessage()` with `MSG_SIM_ADD_FREEFORCE_REQUESTED`, `MSG_SIM_MODIFY_FREEFORCE_REQUESTED` or `MSG_SIM_REMOVE_FREEFORCE_REQUESTED`.
Parameters common to ADD/MODIFY requests:
* 'id' (int) - unique ID of this freeforce, use `game.getFreeForceNextId()` to obtain an unique sequential ID.
* 'type' (FreeForceType) - One of `FREEFORCETYPE_DUMMY`, `FREEFORCETYPE_CONSTANT`, `FREEFORCETYPE_TOWARDS_COORDS`, `FREEFORCETYPE_TOWARDS_NODE`
* 'base_actor' (int) - Unique actor instance ID, obtain it by `game.getCurrentTruck().getInstanceId()`, or if you're in an actor-script, then you can do `thisActor.getInstanceId()` // `BeamClass@ thisActor`is automatic global variable for scripts bound to actors.
* 'base_node' (int) - Node number (0 - 65535)
* 'force_magnitude' (float) - the amount of force to apply, in Newton/meters
Parameters for `FREEFORCETYPE_CONSTANT`:
* 'force_const_direction' (vector3) - constant force direction. Note that Y=up, so to make things float, use vector3(0, 1, 0).
Parameters for `FREEFORCETYPE_TOWARDS_COORDS`:
* 'target_coords' (vector3) - world position to target. For example `game.getPersonPosition()` will target it at position where character is standing AT THE MOMENT.
Parameters for `FREEFORCETYPE_TOWARDS_NODE`:
* 'target_actor' (int) - Unique actor instance ID.
* 'target_node' (int) - Node number (0 - 65535).
Note when any of the actors involved in a FreeForce (be it the base one or target one), the freeforce is deleted.
Example from the PartyBaloon demo mod:
```
// Create the up-force
upforce_assigned_id = game.getFreeForceNextId();
game.pushMessage(MSG_SIM_ADD_FREEFORCE_REQUESTED, {
{'id', upforce_assigned_id },
{'type', FREEFORCETYPE_CONSTANT },
{'base_actor', thisActor.getInstanceId() }, // `BeamClass@ thisActor`is automatic global variable for scripts bound to actors.
{'base_node', UPFORCE_NODE },
{'force_const_direction', vector3(0, 1, 0) }, // Y=up
{'force_magnitude', 0.4f } // Newton/meters
});
```
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Forces work OK, not entirely sure how to attach the balloon to a vehicle though. The above script only works once, trying to remove gives "ID not found": |
Script is broken, I'll fix it and add it to 'examples'.
You need to type out the console variables which the baloon script reads on spawn. In this case, I typed
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FreeForces are global, persistent forces which act upon one node of one actor each. They exist separately from actors and their existing hook/tie/rope interactions. This means they do not interfere with actor N/B or any of the existing linking logic. They're intended for creating special physics effects which aren't supported otherwise, like making party baloons fly. They're intentionally only accessible from scripts to maximize their flexibility and limit maintenance of the codebase.
To manage FreeForces, you use
game.pushMessage()withMSG_SIM_ADD_FREEFORCE_REQUESTED,MSG_SIM_MODIFY_FREEFORCE_REQUESTEDorMSG_SIM_REMOVE_FREEFORCE_REQUESTED.Parameters common to ADD/MODIFY requests:
game.getFreeForceNextId()to obtain an unique sequential ID.FREEFORCETYPE_DUMMY,FREEFORCETYPE_CONSTANT,FREEFORCETYPE_TOWARDS_COORDS,FREEFORCETYPE_TOWARDS_NODEgame.getCurrentTruck().getInstanceId(), or if you're in an actor-script, then you can dothisActor.getInstanceId()//BeamClass@ thisActoris automatic global variable for scripts bound to actors.FREEFORCETYPE_CONSTANT:Additional parameters for
FREEFORCETYPE_TOWARDS_COORDS:game.getPersonPosition()will target it at position where character is standing AT THE MOMENT.Additional parameters for
FREEFORCETYPE_TOWARDS_NODE:Note when any of the actors involved in a FreeForce (be it the base one or target one), the freeforce is deleted.
Example from the PartyBaloon demo mod:
Keep in mind that the physics simulation runs at 2khz (2000 steps per second), while scripts run in sync with FPS. That's why there's no option to add temporary/one-off force impulses from scripts - you are responsible for adding the persistent force, monitoring and adjusting it as needed, and then removing it when no longer necessary. You can create the forces as dummy and then change their type later as needed.
Below is the demo PartyBaloon mod. It weights only 12 grams (0.012 Kg) and under our simulation it moves very slowly, not bypasing a certain threshold, regardless of pull force applied to it. By default, it will just fly off (you can grab it with mouse) but you can use console variables to bind it somewhere:
The script bundled with the baloon will read these variables and create an additional FreeForce towards either the spawn position or given node on given actor.
Download PartyBaloon-12grams.zip
Have fun!