Objects Floating in Water - Revision history

Geep: /* See More */

2021-12-14T23:21:48Z

← Older revision		Revision as of 23:21, 14 December 2021
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	[[Ragdoll Corpses in Water]]		[[Ragdoll Corpses in Water]]

			[[Force Fields]] and [[Func Forcefields]] about AI and cadavers in flowing water.

	{{tutorial-water\|sort=Floating}}		{{tutorial-water\|sort=Floating}}

Geep: Ref to Ragdoll Corpses in Water

2020-04-19T13:52:15Z

Ref to Ragdoll Corpses in Water

← Older revision		Revision as of 13:52, 19 April 2020
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	''By Geep, based on 2019-2020 forum research and experiments done to help create "Away 1 - Air Pocket". Treatment of cadavers is beyond the scope of this article.''		''By Geep, based on 2019-2020 forum research and experiments done to help create "Away 1 - Air Pocket". Treatment of cadavers is beyond the scope of this article; see [[Ragdoll Corpses in Water]]''

	== Two Methods at a Glance ==		== Two Methods at a Glance ==
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	[[Swimmable Water]] by Angua describes setting up water features.		[[Swimmable Water]] by Angua describes setting up water features.

			[[Ragdoll Corpses in Water]]

	{{tutorial-water\|sort=Floating}}		{{tutorial-water\|sort=Floating}}

Geep: /* Getting the Placed Object to Activate */ Add force field

2020-03-14T15:57:43Z

Getting the Placed Object to Activate: Add force field

← Older revision		Revision as of 15:57, 14 March 2020
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	Unfortunately, the object will not rise off the sea floor, or if at the surface, begin bobbing, until after the player activates it by bumping it (perhaps indirectly) or frobbing it. Clever game design may sometimes get around this. For instance, a floating rowboat (i.e., Moveables/Nautical/atdm:moveable_boat2) could be activated by spawning the player directly into it.		Unfortunately, the object will not rise off the sea floor, or if at the surface, begin bobbing, until after the player activates it by bumping it (perhaps indirectly) or frobbing it. Clever game design may sometimes get around this. For instance, a floating rowboat (i.e., Moveables/Nautical/atdm:moveable_boat2) could be activated by spawning the player directly into it.

	~~(Is~~ there a way to activate moveable objects by triggers/scripting~~? Don't know~~.)		It is unclear if there is a direct way to activate moveable objects by triggers/scripting. An indirect way to so activate and keep them activated is suggested in [[Func Forcefields]]: envelop them in a force field. This can be triggered on and off. If the field strength was minimal, object pileup would be delayed. Or perhaps two co-located force fields, only one of which is turned at any time, could be used to slosh activated objects back and forth.

	=== Plausible Behaviors When First Activated ===		=== Plausible Behaviors When First Activated ===

Geep at 19:06, 13 March 2020

2020-03-13T19:06:04Z

← Older revision		Revision as of 19:06, 13 March 2020
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	[[Moveables]] and the older [[DEF Files]] contain info about intended use of the mass and density spawnargs.		[[Moveables]] and the older [[DEF Files]] contain info about intended use of the mass and density spawnargs.

	[[Swimmable Water]] by Angua~~, under [[Category:Water Tutorials]],~~ describes setting up water features.		[[Swimmable Water]] by Angua describes setting up water features.

	{{tutorial-water\|sort=Floating}}		{{tutorial-water\|sort=Floating}}

Geep: Creation cleanup, add template at bottom

2020-03-13T19:00:54Z

Creation cleanup, add template at bottom

← Older revision		Revision as of 19:00, 13 March 2020
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	''By Geep, based on 2019-2020 forum research and experiments done to help create "Away 1 - Air Pocket" ''		''By Geep, based on 2019-2020 forum research and experiments done to help create "Away 1 - Air Pocket". Treatment of cadavers is beyond the scope of this article.''

	== Two Methods at a Glance ==		== Two Methods at a Glance ==
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	=== Getting the Placed Object to Activate ===		=== Getting the Placed Object to Activate ===
	Unfortunately, the object will not rise off the sea floor, or if at the surface, begin bobbing, until after the player activates it by bumping ~~and/~~or frobbing it.		Unfortunately, the object will not rise off the sea floor, or if at the surface, begin bobbing, until after the player activates it by bumping it (perhaps indirectly) or frobbing it. Clever game design may sometimes get around this. For instance, a floating rowboat (i.e., Moveables/Nautical/atdm:moveable_boat2) could be activated by spawning the player directly into it.

	Clever game design may get around this~~, e.g~~., ~~in the case of~~ a floating rowboat (i.e., Moveables/Nautical/atdm:moveable_boat2), spawning the player directly into it.

	(Is there a way to activate moveable objects by triggers/scripting? Don't know.)		(Is there a way to activate moveable objects by triggers/scripting? Don't know.)
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	Based on a [http://forums.thedarkmod.com/topic/5502\|forum post by Ishtvan], [[Func Forcefields]] includes simulating floating objects, potentially many, being transported by current or wind.		Based on a [http://forums.thedarkmod.com/topic/5502\|forum post by Ishtvan], [[Func Forcefields]] includes simulating floating objects, potentially many, being transported by current or wind.

	[[Func Forcefields]] mentions a known problem: a dead body in a river will probably move much too fast, because the water physics code reduces the effective mass of an articulated figure in water. Consequently, impulses applied on AFs in water send them flying.		== See More ==

	~~Treatment of cadavers is beyond the scope of this article.~~

	=== See More ===
	Forum thread [http://forums.thedarkmod.com/index.php?/topic/17828-water/\|"Water"], begun by Destined in March, 2016, is the starting point for information here.		Forum thread [http://forums.thedarkmod.com/index.php?/topic/17828-water/\|"Water"], begun by Destined in March, 2016, is the starting point for information here.

	[[Moveables]] and the older [[DEF Files]] contain info about intended use of the mass and density spawnargs.		[[Moveables]] and the older [[DEF Files]] contain info about intended use of the mass and density spawnargs.

	[[Swimmable Water]] by Angua, under [[Water Tutorials]], describes setting up water features.		[[Swimmable Water]] by Angua, under [[Category:Water Tutorials]], describes setting up water features.

			{{tutorial-water\|sort=Floating}}

Geep: Created from offline doc

2020-03-13T18:34:14Z

Created from offline doc

Show changes

Springheel at 00:25, 17 July 2019

2019-07-17T00:25:21Z

← Older revision		Revision as of 00:25, 17 July 2019
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	\|Doesn’t float		\|Doesn’t float
	\|-		\|-
			[[Category:Editing]] [[Category:Water]] [[Category:Tutorial]]

Springheel: Created page with "''Written by Geep, 2019'' Entities found in the “Movables” folder will float dynamically in water if their calculated density is light enough. But there are issues. == A..."

2019-07-17T00:23:58Z

Created page with "''Written by Geep, 2019'' Entities found in the “Movables” folder will float dynamically in water if their calculated density is light enough. But there are issues. == A..."

New page

''Written by Geep, 2019''

Entities found in the “Movables” folder will float dynamically in water if their calculated density is light enough. But there are issues.

== Adjust the “Mass”, Ignore “Density” ==

To control floating and underwater behavior (detailed below), you may wish to inspect and override the inherited “mass” spawnarg value. If a mass value is defined - and it always is if you use a standard moveable class - then the “density” spawnarg is algorithmically ignored… so you can ignore it too.

Remember that the mass of an object can affect non-water aspects of game play.

== Desired Initial Placement of an Object ==

This restates general considerations when placing a Moveable in the map, but in a water context.

''In the Water, but Above the Sea Floor.'' By “sea floor”, we just mean the first solid object encountered directly below the object. Place the movable object where you wish (below, at, or slightly above the water surface), and set its “nodrop” spawnarg to “1”. On worldspawn, it will stay where you placed it, awaiting activation by the player.

''On the Sea Floor.'' Like the above, but make sure nodrop = 0 (the usual default). On worldspawn, the movable will move immediately to the sea floor (without special effects), awaiting activation by the player.

''Far Above the Water.'' If the object is placed far above the water or any other floor, it just hangs there (awaiting player activation), no matter the nodrop value. If the player is swimming, the object will be out of reach.

== Getting the Placed Object to Activate ==

Unfortunately, the object will not rise off the sea floor, or if at the surface, begin bobbing, until after the player activates it by bumping and/or frobbing it.

Clever game design may get around this, e.g., in the case of a floating rowboat, spawning the player directly into it.

''[Is there a way to activate objects by triggers/scripting?]''

== Plausible Behaviors When First Activated ==

Objects initially placed above the water surface or higher in the water than they would normally float may trigger splash sound and visual effects, and plunge below the surface (before arising if buoyant). Similarly, initially underwater objects that are highly buoyant may pop above the surface, with effects.

As in real life, the presence and extent of such behaviors is presumably influenced by the momentum at surface penetration. But the engine likely scants object shape and orientation.

== Effect of Mass on Buoyancy and Floating Behavior ==

The mass divided by the calculated (or estimated) volume gives a calculated density, which affects how high in the water an object sits and (along with mass) how vigorous any bobbing and roll-about may be.

The following summary table gives rules of thumb, based on experiments detailed further below. For box-shaped objects it is possible for both you and the physics engine to easily calculate the volume, and from that (given the mass) the density. For other shapes, the engine likely deploys shortcut estimates (perhaps using the collision model) with ad-hoc fudge factors. Rather than attempt to mimic that (or guesstimate appropriate volumes for corpses or complex prefabs), you might use the table as follows:

# Observe the object’s floating behavior, and from that, impute its approximate density.
# Compare that to the desired behavior, and scale the mass value proportionally.
# Iterate until happy.

{|
! style="text-align:left;"| Estimated Density
! Underwater: Sink (&dArr;) or Rise (&uArr;)
! Float Behavior at Surface
|-
|1.8
|&dArr;&dArr;&dArr;
|Doesn’t float
|-