transparent box in doom

[camper]

Is it possible to create a transparent square/rectangular sector with a height in the doom port? Or a transparent 3D floor? That is, a transparent box inside which any 3D model could be placed?
An analogue of the “clips” in the assault cube, see the picture in the spoiler.
This isn't currently in any doomport, so the question doesn't seem to fit current topics, which is why it's as a "what if?"
 

Spoiler

 

Edited September 9, 2023 by camper

[SilverMiner]

make a 3d floor with alpha 255 maybe?

[RataUnderground]

You can use midtextures to create that effect, however, if you are going to use 3D models anyway, why not use a 3D model shaped like the edges of a cube?

[Kinsie]

1 hour ago, SilverMiner said:

make a 3d floor with alpha 255 maybe?

Yeah, 0-alpha 3D floors are what we've been using in Reelism 2 whenever we've needed more nuanced collision than midtexes could provide, like the sloped rails in Astrolab X.

[camper]

48 minutes ago, RataUnderground said:

You can use midtextures to create that effect, however, if you are going to use 3D models anyway, why not use a 3D model shaped like the edges of a cube?

The 3D model itself does not have collisions in doomports. And if used as an actor, then the actor has a collision radius, which does not allow making elongated objects.

[Jayextee]

Can you not make an invisible 'thing' with the width as its radius, plus the right height, and then place to together to make the rectangular collision area of the model?

[RataUnderground]

59 minutes ago, camper said:

The 3D model itself does not have collisions in doomports. And if used as an actor, then the actor has a collision radius, which does not allow making elongated objects.

Ah, what you want is to create a collision zone so that the player does not go through the model, not the graphic effect of the colored lines on the edges?

Why not create then a series of linedefs with the appropriate silhouette for the collision zone and mark them as impassable or player blocking?

Edited September 9, 2023 by RataUnderground

[camper]

Yes, I know these ways of creating collisions. But I’m asking an abstract question specifically about the possibility of creating an impenetrable transparent box with a 3D model inside on a 2.5D engine, with the ability to pass under and over it, but not inside it.

Edited September 9, 2023 by camper

[camper]

It seems can make a cage from 3D lines. But I’m not sure if they exist anywhere else except Risen3D.

https://md2.sitters-electronics.nl/tut_lines.htm

[camper]

Just to show how easy it is to do this in a related 2.5D engine. (Sometimes it seems to me that Aardappel started the cube project as a visual editor for doom maps).
media.mas.to/masto-public/media_attachments/files/111/042/796/544/992/022/original/ad5b0dd6ec6afcc6.mp4

[Kinsie]

On 9/10/2023 at 6:04 AM, camper said:

Yes, I know these ways of creating collisions. But I’m asking an abstract question specifically about the possibility of creating an impenetrable transparent box with a 3D model inside on a 2.5D engine, with the ability to pass under and over it, but not inside it.

I mean, in GZDoom at least every 3D model is an actor, so you've got a collision cube right there.

 

For anything more complicated, like I said, there's invisible 3D floors.