ZDoom

As the title says, how can I get a dynamic light to move with a floor (UDMF).

e.g. Imagine I have a dynamic light placed 32 units above a floor. The floor is a lift activated by a line type 62 (platform lower, wait, raise). The thing is, the platform will lower and raise but the light stays at its absolute Z position.

Lift up:

Lift Down:


I thought that there was some way to force actors to move relative to the floor, but I can't see it anywhere.

What I have done in the past (a long time ago) is make an invisible actor with a light attached that (continuing the above example) is set with a vetical offset of 32 units. That way, the actor moves with the platform and, therefore, so does the light. However, this is far from flexible - requiring a new actor for each light size/colour/offset. So, is there a way to make the standard built-in light objects move relative to the floor (or ceiling I guess) when the floor moves?

Do we get in trouble if we both ask essentially the same question?

Ok, so to get a light that you can move about, you need to define a dynamic light in GLDEFS and bind it to the frames of a dummy object you place in the map.

The solution, at least this is my next attempt at a workaround, is to allow the dummy object to ride the lift (give it gravity), and just offset the light on the Z axis in its GLDEFS definition.

Note that what I present below is the old code, we both need to give the thing gravity and use the GLDEFS offsets.

Spoiler: ZScript for my dummy objects

---

Code: Select all

class VASKM_ElevatorLight_Upper : actor
{
	default
	{
		//$Category Environment
		
		height 1;
		radius 1;
		
		+NOGRAVITY
		+NOCLIP
		+NOBLOCKMAP
	}
	
	states
	{
		spawn:
			VMEL A -1;
			stop;
	}
}

Spoiler: GLDEFS Creating/Binding the Lights

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Code: Select all

// Lights for the VASKM Elevator
// Upper Light
pointlight VASKMELU
{
	color 0.59 0.59 0.75
	size 48
	offset 0 0 0
}

// Lower Light
pointlight VASKMELL
{
	color 0.29 0.29 0.38
	size 64
	offset 0 0 0
}

object VASKM_ElevatorLight_Upper { frame VMEL { light VASKMELU } }
object VASKM_ElevatorLight_Lower { frame VMEL { light VASKMELL } }

Edit: let me quickly add, Enjay, offset vertically using the Y axis, not Z, the GLDEFS wiki explains that, Y is vertical like a model!

I think you have just suggested the same method that I mentioned in my post?

Enjay wrote:What I have done in the past (a long time ago) is make an invisible actor with a light attached that (continuing the above example) is set with a vetical offset of 32 units. That way, the actor moves with the platform and, therefore, so does the light. However, this is far from flexible - requiring a new actor for each light size/colour/offset. So, is there a way to make the standard built-in light objects move relative to the floor (or ceiling I guess) when the floor moves?

Oh, duh, you know what, it's the same method I've used in the past to make stuff like flashlights. Hmm I'm stuck making anything flexible, I think ideally what we both want is to have them follow the same rules as any other actor. My guess is, for example, the pointlight is sort of a baked light by itself and not when bound to another objects frames.

I have to say that I haven't worked with UDB (I assume you are working with UDB), my editor is much more basic, so what I say is theoretical. But as far as I understand, the light in UDB has fields for light color and light intensity that you can fill, and that's how you work with them. So I would have tried making a new actor that inherits from PointLight (assuming that PointLight is the thing that UDB places in the map when you choose to create a light in that spot), but additionally has a RELATIVETOFLOOR and/or MOVEWITHSECTOR flag(s). Then, if UDB is smart enough, when you place this actor in the map, it's gonna have the same fields available for filling; and when you need a floor-bound light, you place this actor instead of the standard light.

Or, alternatively, one could make a feature request of the UDB developers to have a new checkbox in the properties of a light, call this checkbox "floor-bound" or somesuch; and when this checkbox is ticked, this particular light would be given a MOVEWITHSECTOR flag, or some other flag (or their combination) to ensure that it stays relative to the floor; I'm sure UDB developers would know better which flag(s) to assign.