Hi @Thorsten09,
Went to the Arcade (https://www.mainevent.com/) Yesterday and played…
Awesome Light Gun Rail Shooter Fun. These games keep you so busy shooting you don’t have time to do anything else LOL.
All You Do is Shoot!
Inspired
Of course, after having all this fun at the Arcade playing Alien Armageddon and others. I found New Railshooter Inspirations!
In Aliens Armageddon the FPS Weapon-In-Corner caught my attention. It sparked ideas of blending a True FPS and Railshooter together, seamlessly switching between the two on-demand and scripted. I prefer True First Person using Full 3D Body + Camera Mounted to head socket OVER Arms only Approach and always up for a debate on this topic. hehe.
Daily use of V8SUPERCAM influenced thoughts about game play in multiple perspectives from Top Down to First Person. Actually many Railshooters offer this. I desire to push it to the extreme. I also thought about offering Avatar + Reticle (Cursor) visibility options: Avatar + Reticle, Avatar Only, and Reticle Only. I believe the Reticle Only offers another First Perspective slightly different than common Weapon-In-Corner First Person.
More than Meets the Eye
I definitely want to do something elaborate with Reticles. 
No Sprites. Give it as much love as the Weapon itself. Make it full 3D with PBR Materials ( Metallics 
), Animations, VFX, and SFX. Reticle Customization! I think I handle the modeling of reticles.
Mind, Body & Guns
As I continued to ponder my thoughts, I went deeper into a Manual & Procedural Implementation. Splitting into 3 sections:
- Avatar Body Movement
- Camera Focus / Rotation
- Weapon (one or more ie Dual Wielding) Selection, Targeting, Aiming and Firing.
I could offer on-demand Procedural | Manual Play Control of the Sections, or Selection of pre-created Play Control Schemes between the sections allowing the player to experience the game with different types of Play. I even gave the Play Control Schemes names. haha:
- Run & Gun - Manual Bod + Auto Cam + Manual Dual Guns
- One Arm Bandit - Manual Bod + Manual Cam + 1 Manual Gun / 1 Auto Gun
- Evil Eye - Manual Bod + Manual Cam + Auto Dual Guns
- Full Auto Pilot - Auto Body + Auto Cam + Auto Dual Guns
Mount & Focus
I already handle the sections manually, thus, I ponder more so on Procedural Implementation. I view the Task of developing a Procedural Railshooter as a matter of automating Camera Location and Rotation. Because, All You Do is Shoot!
With this notion, one does not necessarily need to move the Camera along a static conceptual rail such as a spline, but create a dynamic, fluid conceptual rail of movement by interpolating Camera Location and Rotation.
Instead of applying location and rotation directly to the camera, we use two objects that we can manipulate independently and dynamically to control the Camera Location and Rotation in the same fashion. These two objects are called: Mount and Focus (Look At Target).
Mount is the Object the Camera attached to. We move the Mount to control the Camera Location. Focus is the Object that Camera Rotation is locked on. We move the Focus to control the Cameras Rotation. Simply change the Mount and Focus and interpolate between previous and new location/rotation.
Procedural Railshooter
Step 1: Auto Bod
A Character Pawn can be AI Controlled using UE Navigation Subsystems. This is my go to (pun intended) as I’ve already have worked with this system. I consider this to be the first and easiest step to take towards an Automated Railshooter System.
I anticipate the need to implement a form of Decision Making Algorithm {Behavior Tree, State Tree, State Machine, Rules-based Stack, etc} to determine and priority for Paths to Take, Pause Movement, Execute an Event: Cutscene Execution, Spawn Actors, and other Actions.
Step 2: Auto Cam
Continuation with the concept of Mount & Focus, Attaching a Camera to an object that can be moved is commonplace. Cameras are often attached to player controlled Pawns. For Automated Camera Location I’m attaching the Camera to a Pawn Character Body that uses AI Navigation.
Automated Camera Rotation is the job of the Focus Object and a Focus Object can be any Persons, Places, Things deemed relevant for the Player. Like Movement, I would implement a form of Decision Making Algorithm to determine and Focus Object Priority. Underlining Factors of the priority could be based on Player’s goals of maintaining health, acquiring wealth, acquiring high score.
V8SUPERCAM already functions as highly dynamic multi-perspective camera system based on the concept of Mount and Focus. I would use a Decision Making Algorithms to manage and execute on-demand switching of cameras with the same functions Players use to do it manually. This would be my approach to handling Procedural / Manual Play Control for Body, Cam, Weapons.
Step 3: Auto Gun
I want Dual Wielding in my Rail Shooter. Why pause the action when you need a break, keep SHOOTING. Don’t have a friendly Bot handy to assist, You have another Hand Gun to enlist.
Prototyping
I was too excited after my trip to the Arcade so I jump on the workstation and immediately started testing my ideas.
Using previous Character Bot AI to use waypoints to move between locations. I attached the Possessed Player Character with Cameras using the same Skeleton to the Bot and sync the skeletons.
PROCEDURAL RAILSHOOTER - First Step. AI Navigation. - YouTube