I've been giving thought lately to how it could be possible to make star systems in Limit Theory realistically-sized (on the scale of dozens of astronomical units) while still maintaining a general Freelancer-like feel to travel and without breaking other mechanics.
This proposal offers some suggestions for the implementation of intra-system travel to allow for realistically-sized systems without making travel within star systems too time-consuming. I will warn at this stage that this thread will heavily reference Heisenberg technology, since it is the only way in which the implementation details can be plausibly justified.
There are both positive and negative effects that implementing realistically-sized systems could have on gameplay:
- More plausible and immersive - improved realism will help make the game world feel more genuine and allow for easier suspense of disbelief on the part of the player. It will also help convey the feeling of being a small fish in a much bigger pond.
- Allows for interesting travel - there is more variety and scope for intra-system travel that can make traveling through star systems more interesting and engaging.
- Allows for greater seclusion - if they so wish, the player can travel to remote parts of the system and be surrounded by billions of kilometers of nothingness in all directions. They can choose to set up bases in these locations if they want.
- High-velocity motion can be extremely satisfying to the player.
- Risk of detraction from Freelancer-feeling - it may not be possible to capture a truly Freelancer feel with realistic system sizes. This will need to be investigated.
- Greater separation between agents - agents will tend to see and meet each other at and around points of interests, such as planets and asteroids, but not so much at arbitrary points in the system.
- More tedious/frustrating travel - more thought would have to be given to travel, which some may find annoying.
- Greater implementation difficulty - may be too resource-demanding or difficult to implement.
I envisage that there could be multiple modes of travel within a system, each allowing for different rates at which distances can be traversed. In particular, I envisage four distinct mechanisms, from slowest to fastest, with approximate velocity ranges included:
- Heisenberg-drive (normal)
- 1*101 m.s^-1 - 1*104 m.s^-1
- Heisenberg-drive (cruise)
- 1*104 m.s^-1 - 0.01 AU.s^-1
- HAVE Lanes
- 0.01 AU.s^-1 - 0.1 AU.s^-1
- Transfer Lanes
- 1 AU.s^-1
At the lowest rate of travel there is the H-drive, which would be the ubiquitously used propulsion technology that vessels in Limit Theory would rely on. Information on the Heisenberg drive can be found in this thread. This technology would allow for vessels to travel around up to around a few kilometers per second, and are fairly maneuverable at these speeds. They require significant but not overly expensive allocations of power and CPU at these speeds. Agents will be able to operate a number of other systems while traveling in this mode, including weapons, sensors, etc.
This mode of travel can be used anywhere within a system.
As the H-drive moves through space in a straight line, it is able to cache data in a way that allows for better extrapolations of the quantum fluctuations of the vessel's particles (see here). This has the effect of allowing the H-drive to accelerate i.e. increase it's apparent velocity. As the H-drive continues to move at faster and faster velocities, it becomes increasingly restricted in its ability to change its heading without slowing down. However, so long as agents continue to move in a straight line without making any changes to their course heading at all, they will be able to achieve velocities far beyond the few kilometer per second restrictions of H-drives used in their normal mode. The agent's vessel will begin accelerating slowly at first, but will steadily increase up to a point before decreasing again - in other words, the H-drive has initially positive but linearly decreasing jerk. This allows the H-drive to quickly build up speed until it attains superluminal velocities (capped at around 0.01 AU.s^-1 or 5c). The velocity characteristic of the H-drive as it transitions between normal mode and cruise mode is shown below.
The H-drive operates by rapidly "jumping" the vessel's constituent particles between points in space. In normal operation, it is able to do this millions of times per second. At its maximum attainable velocity of around ~5c, the H-drive would be performing jumps trillions of times per second. Due to the extremely fast jump rate of the vessel's particles, they will not have time to electrostatically interact with other particles, giving them an almost ghost-like quality that prevents them from colliding with most other objects. This would have two implications:
- It would warrant some kind of partial transparency effect for vessels while traveling at these very fast velocities.
- It would reduce or eliminate the need for collision detection, significantly reducing the load on the physics engine. The point at which collision detection is reduced or turned off for the vessel can be used to distinguish between "normal mode" and "cruise mode".
In this mode, the H-drive can only be used to travel in a straight line and has very expensive power and computational demands. Like in Freelancer, weapons and most other systems ordinarily cannot be used during this time. In order to avoid the player inadvertently ordering their navigation systems to change heading while trying to achieve cruise velocities, some button or other mechanism should be available to the player to let them lock their current heading. Trying to change heading at high speeds will lead to a significant reduction in velocity and will cause the H-drive to revert to "normal mode". As with "normal mode", "cruise mode" can be used anywhere.
I would also like to see modules that can "disrupt" the H-drives of other agents as they're in cruise mode in order to bring them back down to "normal mode" velocities.
HAVE lanes (rhymes with "shave" or "wave"), or high-accessibility vacuum energy lanes, are naturally-forming bands of space with extremely high-accessibility to vacuum energy. The original discussion of this idea can be found in the Heisenberg Extractor thread under Terrain. In brief, I imagine that vessels in Limit Theory are all equipped with exactly one special kind of energy production module, called an H-Extractor, just as all vessels are equipped with exactly one special kind of propulsion module (the H-drive). H-extractors are able to provide a continuous source of power to vessels by extracting energy from the vacuum of space. Different parts of space allow for different levels of accessibility to this vacuum energy, and this will dictate how much power H-Extractors are able to generate. Running through systems are these bands where access to this energy is extremely easy, and H-extractors are able to maintain very high rates of power generation as vessels fly over these regions. This additional power can be routed through to the H-drive, where it allows for much stronger H-fields to be generated and therefore longer jump distances.
Agents will be able to analyse space to find these natural lanes and task their navigation systems to follow along them. As with ordinary H-drive operation, vessels will start out slowly and gradually built up velocity. However, since the distance that particles cross in each jump significantly increases, the H-drive is able to maintain the same apparent velocity of the vessel at a slower jump rate. This allows the H-drive to achieve superluminal travel rates (of around 0.1 AU.s^-1 or 50c) while still keeping its jump rate low enough for the navigation computer to make the calculations necessary to allow the vessel to steer and change heading to follow the course of the HAVE lane that it is tracking.
The gif below demonstrates the kind of feel I expect HAVE lanes to have while the player travels along them.
As with H-drives in cruise mode, I envisage partial transparency and no collision detection for vessels traveling via HAVE lanes.
Transfer lanes are the "trade lanes" of Limit Theory. I have been researching into how trade lanes were implemented in Freelancer and have designed these in a way to hopefully give a very similar feel to that game. Transfer lanes are essentially very, very large transfer units, and operate by producing H-fields that extend across vast distances within star systems. At each end of a transfer lane is a transfer gate that sustains it. These gates are connected together to form a network through which agents can move around systems at extremely fast rates (up to 1 AU.s^-1 or ~500c).
These transfer gates would be located close to major points of interests - planets, large stations, jump gates, etc. One idea that I've had is for these gates to orbit planets and other large bodies, which in turn would orbit the local star. Over time, the changing relative positions of all of these bodies would cause the straight-line paths between gates to become clear or blocked, and this would lead to a dynamically-changing transfer gate network. This can lead to dynamic and cyclically-recurring effects upon the economy of systems and regions in Limit Theory. This idea is presented visually below.
However, Josh has confirmed that celestial bodies would be static in Limit Theory, and so dynamically-changing networks are not a suggestion I have for Limit Theory, but perhaps instead for any future sequels. I would be happy enough to see static transfer gate networks in LT1.
Transfer lanes have the following characteristics:
- They exist along straight-lines.
- They are completely artificial and require transfer gates to exist.
- There is the possibility that agents can construct and own them, and also toll other agents for their use.
- They allow for traversal across systems in the space of minutes.
- They may allow entry into them at any point along their length, or possibly only at one of the transfer gates. This will need to be decided upon at some point.
- Each gate may be shielded to vaporise dangerous matter getting propelled down the lane, such as asteroids or debris. If this is the case, it would mean that vessels would need to maintain shields as they enter and exit from transfer lanes, as they would need to rely on fully-synced interactions between their shields and the gate shields to pass through them without damage. This can lead to some interesting tactical gameplay - shooting down an agent's shields could prevent them from entering a transfer lane, for instance.
- There is the possibility that hostile agents can disrupt transfer lanes as you travel through them, as in Freelancer. However, based on the videos I saw of this and a similar mechanic featured in X: Rebirth, people tended to find this mechanic annoying. Therefore it may not be a desirable mechanic to implement in Limit Theory. On the other hand, the reason that people may have found this feature annoying in those other games may be because they were pre-scripted events and therefore felt artificial and like "grinding". In Limit Theory, if an agent chooses to disrupt transfer lanes as you or another agent passes through one, they will do so for very specific reasons that they have in mind.
All of these proposed mechanisms of travel would be used in a kind of hierarchical manner to travel between arbitrary points in a solar system. H-drives offer the slowest travel times but can be used anywhere; HAVE lanes are faster but exist only across certain regions of space; transfer lanes are faster still but there are fewer of them than HAVE lanes. Agents would usually begin by gearing up their H-drive, then switching it to cruise mode and directing it towards the closest HAVE lane, which they will then travel along until they reach an entry point to a transfer lane. They will use the transfer lane network until they find an appropriate place to come off it, and then use a HAVE lane to reach another point much closer to their destination, and finally travel to their destination using the H-drive. This parallels what happens in real-life, where vehicles will likely get from one point to another by using residential roads, A-roads and motorways.