Parallaxing Sky Viewpoint/Source Engine-like 3D Skybox

Information:

Type: Custom sky camera
Connections: None (Inherits from a built-in (G)ZDoom actor.)
Spawn Offsets: Where the camera will be is determined by the mapper themselves/
Spawn Ceiling: No, can be raised to it in-editor.
Variants: None
Summon: ParallaxingSkyViewpoint
Brightmaps: N/A
Actor Modification: Only inherits from the pre-existing SkyViewpoint that is inside the engine archive.
ACS: No

Credits:

Code: inkoalawetrust (Improved code), DrPyspy (Original base code)
GLDEFS: N/A
Sounds: N/A
Sprite Edit: Custom sky camera graphic by Tabijaky, made from GZDB/UDB's sky viewpoint graphic.
Idea Base: Source Engines' 3D skyboxes.

Description:
An improved variant of ZDoom's existing static sky viewpoint actor, unlike the ZDoom sky camera, this camera will move relative to the players' camera, making it so you can move closer or further from objects like distant hills that exist within a skybox sector, instead of the camera staying in place, similar to 3D skyboxes in the Source Engine. The amount of parallax can be changed through the User_SkyParallax use variable. For more info, read the DOCUMENT.txt file.

Sprite/In-editor graphic:



Download link: https://drive.google.com/file/d/1rdoqY-MlMCX0-xGZDLbsO-G8zX7wwOVV/view?usp=sharing

This is a submission I've wanted to make for about a month, the code for it was already finished and I've even used this sky camera for some of my unreleased maps already. 
The only thing that was missing was a custom sprite for the actor, to not use the pre-existing graphic for the normal sky viewpoint. But earlier today I finally got around to having someone make that graphic (Tabijaky), though originally I wanted to make it myself. Also I'm not really sure where it would fit, so I decided to post it here in the SFX Shoppe.

The original code was written by DrPyspy and used with his permission, while I'm the one that updated it, such as by adding the User_SkyParallax variable, so the mapper can control how much the sky camera moves relative to the player without having to change the cameras' source code.

Also if I can, tommorow I'll make and attach a video here of this sky camera actor in action.

inkoalawetrust wrote: Also if I can, tommorow I'll make and attach a video here of this sky camera actor in action.

A demo map (again, something minimal and basic) bundled with the submission would be preferable. As it is, I can't really check this out.

I updated the submission ZIP archive, so it now includes the demo map you asked me to make of the parallaxing sky camera in use.

Also you probably didn't notice, but the demonstration map of the main battle tank submission also used this parallaxing sky camera, that's how the buildings in that map moved closer and further away, they weren't actually inside the map .

Also the reason the parallaxing camera doesn't have the custom icon in the linked editor screenshot is because the map was made before the icon was.

Added

inkoalawetrust wrote: Also you probably didn't notice, but the demonstration map of the main battle tank submission also used this parallaxing sky camera...

Yeah, I didn't, since I was focused on testing the tank.