I have improved the sprite for the re-entry effect. It still needs some polishing, but now the re-entry effect looks like this up-close.

An extra bonus picture:

Plus a video of the sky, sun, moon and clouds all blending together with the mask:

Tachy, a friend of mine, helped me considerably by calculating a star catalog for the year 2994 (when the events of the game take place). Some of the stars experience a considerable drift over the 1000 years - it might not be a very important detail to most players, however it is a nice little detail to have.

Here is a simple comparison between the two starfields:

The newer year 2994 catalog also contains way more stars - 119,614 total. The older catalog has been truncated to only magnitudes brighter than 9.99, so it only listed 28,593 stars.

The synths sensors are sufficiently sensitive to pick out faint stars, so in the end I plan to include all ~120,000 stars (though possibly less based on performance settings, however it does not seem to be considerable for the particle system).

Below are the two starfields in higher resolution. These images can be opened at a higher resolution, if you want to take a closer look.

Epoch 2000

Epoch 2994:

Here is the video of the star field movement over time and how it blends together with the clouds using the mask shown in an earlier post.

While working on the sky system, I had a thought about adding random space debris re-entering atmosphere. It would be a really telling and interesting piece of narrative that illustrates the state of the world - in the setting of Synesthesia, in year 2994, most of the space operations have been abandoned and overall there is no organized effort to monitor space debris anymore.

There are still millions of objects in orbit - many of these are private satellites, spacecraft and other assorted hardware. There are a few large objects (space stations and old spacecraft) which will eventually decay and re-enter atmosphere. All sorts of debris routinely enters the Earth atmosphere.

A large proportion of this debris is the result of the progressing Kessler syndrome, making any space travel dangerous and forcing people to abandon many of the space-based operations.

The player would be able to see these happen randomly. Many of them may be too small to notice unless they get lucky, however there may be a really big event once in a while.

The re-entry effect is implemented as a particle system combined with a fairly simple thermal simulation. The debris objects are spawned at the height of about 120-140 km and are given a random, statistically distributed direction & entry angle.

The objects continue to fly free and a simple break-up model is used to calculate when the object finally burns up. It is a fairly simplistic model, it is possible that I might improve it in the future.

One definite improvement I want to make is using better sprites - it would make the re-entry trails much more distinct, vivid, and less blurry. It would also emphasize multiple objects traveling in the re-entry path as the main object continues to shed debris.

The video below shows a better look at the hot entry and break up of the object. The re-entry event, if detected by players information systems, will also be recorded in the minor event log.

The re-entry events are defined by the following parameters:

1. Object mass - this defines how much debris is generated and how long can the object withstand high temperature.
2. Burn rate - this defines how fast temperature burns up the mass of the object or causes debris shedding events. The effective burn rate is proportional to this value and the current temperature.
3. Entry vector - the simulation has a simple exponential model of atmosphere, so shallow and steep re-entries look distinctly different.

A combination of these parameters can be used to set up a re-entry that looks most artistically appealing. The sky system creates random procedural re-entry events. For special scripted events, the same particle system can be created manually and multiple systems can be combined to create an appearance of a very large object breaking up.

Here is a close-up picture of the re-entry event. For prototyping, I’ve been using a simple spherical sprite, which makes the entire trail look quite blurry. The quality should improve considerably when the sprite will be more drop-shaped, with a large glowing core and a small trail following it.

In addition to immersion, I want to include the re-entry effects in at least two elements of the narrative itself:

1. A side quest, during which the player can force a spacecraft in orbit to burn its engines for re-entry. While not having effect on the main quest, it would be narratively connected to the plot events.
   • The destruction of this spacecraft would be done to hamper the mercenaries and Eden, the primary antagonists of the game.
   • Most likely, this spacecraft will be an orbital weapon station, somewhat resembling SOL from Akira
2. A random event, during which an object re-enters over the EDZ-01 and visibly reaches surface.
   • After re-entry, a glowing object falls somewhere in an obvious area, allowing player to go investigate and find this object.
   • Possibly, the object is a new friend or an enemy, as well as some unique hardware.
   • The side quest rewards player for the exploration they had to do in order to find the crashed object.

(this entry is a work in progress, last updated: 2023-06-26).

These are the different elements considered or planned for Synethesia.

Narrative Gameplay Elements

These are the gameplay elements that enhance the narrative, provide extra flavor or information to player and may be used as part of a quest.

1. Computer terminals
   • Similar to dialogs, but longer text replies and shorter user prompts.
   • Computer terminals reveal extra lore information and allow triggering special events in the game world.
2. Dialogs with NPC’s
   • The main way player interacts with the characters in the game world.
   • Dialogs allow player to interact with the given character similarly to RPG games (I am using Fallout: New Vegas as a reference).
3. Background NPC dialogs
   • Single sentence reactions NPC’s may say when player presses USE on them.
   • These simply provide background flavor and indicate NPC’s which do not have a dialog tree.
4. Infoscan 1: Scanning landmarks or target zones
   • Information or clues can be gained by manually scanning landmarks or target zones.
   • Player enters the scanning mode by holding the SCAN key and points cursor at a landmark or a zone of interest. This reveals a short message that can be a helpful clue.
5. Event Log. Infoscan 2: Automatic landmarks or target zones
   • Some landmarks get automatically scanned by simply approaching them. The short text is then added to the rolling event log.
   • The event log also includes redundant text from other narrative elements, as well as general background noise for flavor.
   • Some landmarks and clues are pretty obvious and are visible with the naked eye, however the infoscan system can still provide just a little bit of lore.
6. Radar
   • Reveals hidden landmarks and passageways, reveals information unseen normally. Radar allows player to ‘see through walls’.
   • Radar also provides a small 3D minimap that player can toggle.
7. Radio frequency scanning
   • Produces audible noises, words, music, images and other narrative elements, plus flavor text and quest triggers.
   • Most radio signals are produced by various landmarks around the city.
   • Satellites that pass over player also produce radio signals, however most of them simply broadcast a dead carrier or repetitive telemetry.
8. Scavenger background chatter
   • Text-based messages sent by scavengers to each other over their public network.
   • Player can turn the optional messages off, however quest-specific text messages will still get delivered to player.
9. Enemy background chatter
   • Communication between enemy AI units, coordination, reaction to player.
   • These work similarly to scavenger chatter, however they are mostly produced by the dynamic AI system rather than world events.
10. Primary narrative
    • The main quest that starts automatically and guides player into more of the game.
    • The user interface that displays quest goals, quest log and other information.
    • The quest markers.
    • An extended event log that includes all dialogs and other text messages player has seen or heard.
11. Item descriptions
    • Hovering over an inventory item will display its technical parameters as well as a general text description.
    • These descriptions can contain unique lore beyond just technical specifications
    • This includes notes and documents, as these items only present information through their description.
12. Technical drawings inspection mode
    • A combination of player reward and extra lore, the game will let you view some select drawings in high resolution.
    • This also includes things like maps and posters potentially, however this would be a fairly limited and minor element.

Functional Gameplay Elements

These are the elements that have to do with the actual primary gameplay loop.

1. WASD movement
   • Standard first/third person shooter movement controls.
2. Lean left / right
   • Character can lean left or right to “pie” corners.
3. Jumping
   • Jump height is limited in this game in order to give a heavier feel to the player.
4. Climbing
   • The character can climb moderately tall obstacles (1.6 m) in order to get to places that could not be reached otherwise.
   • Same mechanic allows to vault over obstacles if they meet appropriate height.
5. Weapon length
   • The player character has a unified rig. The weapons collide with the environment and deflect in order to fit in narrow spaces.
   • This means that shorter guns would be required for comfortable use in-doors.
   • It also requires player to be aware of their tactical positioning relative to obstacles. A long rifle can get stuck on an obstacle that is too close in front of the player.
6. Weapon condition
   • Firing shots from the weapon depletes condition, requiring the weapon to be periodically repaired.
   • Bullets impacting the weapon when it is in hands or in the backpack also degrade the condition, however the weapon provides some bullet protection.
7. Worn item condition
   • Worn items have condition that degrades when player gets hit.
8. Primary / secondary reload
   • Some weapons require two types of consumables (for example, bullets and fuel).
   • Player can separately reload either consumable in the weapon.
9. Realistic gun mechanics and weapon failures
   • The full cycle of the conventional weapons is recreated. Detailed simulation model allows for a more lively response of the weapon to failures.
   • The intent is for player to get attached to their weapon, making it unique over the span of the game.
10. Weapon upgrades
    • Weapons can be upgraded. All weapons have a generic set of upgrades that provide minor to moderate improvements to gun performance.
    • Each weapon also has a gimmick upgrade tree, which boosts a single parameters of this weapon beyond reasonable values, allowing players to explore ultra-specific niches.
11. Environment hazards
    • Various hazards drain players health points or disrupt their vision, hearing or other aspects of their operation.
12. Non-functional technical artifacts
    • These items provide a short lore text message and are sold for an increased price.
    • They can be widely found around the zone, making them almost clutter-like, however still fetching a good price.
13. Functional technical artifacts
    • Some technical artifacts can have special functions or provide player with additional abilities.
    • Additional items like the external targeting computer allow player to gain a corresponding perk from their perk tree while they are wearing the item.
    • Technical artifacts may have expansion slots that change their operation or upgrade them.
    • The functional technical artifacts can be found or bought from traders in very limited amounts.
14. Realistic ballistics
    • A simulation model predicts ballistic dynamics of a bullet and energy dynamics of the weapon itself.
    • Wind affects bullet path, as well as the weapon zeroing and physical parameters.
    • This mechanic serves to limit the pace of the game to tactical, requiring higher care and skill to engage targets from longer distances.
    • Bullet penetration.
15. No weapon sway, weapon holding dynamics
    • Player experiences recoil from the weapon, however there is functionally no natural weapon sway.
    • The players character is a synth with strong artificial muscles.
    • Heavy weapons slow down the aim stabilization mechanics, leading to more inertia and less accuracy from rapid movements.
16. Data points / Experience points, Perks
    • Works similarly to Fallout: New Vegas. Data points are awarded for performing various in-game actions, passing speech checks, completing quests and so on.
    • Each time player levels up, they can select an additional perk that enhances their gameplay abilities or adds new features.
17. Inventory, in-world items and containers
    • Player can pick up items in the world, from containers, from traders or from NPC bodies.
    • The inventory is grid-based, where number of cells is proportional to the volume taken up by the item.
    • Player has a dominant hand into which active weapon is equipped.
    • The non-dominant hand is used to load and unload ammunition from the gun.
18. Harnesses
    • Harnesses are special items which allow player to use a button to equip or use a specific item, usually a weapon.
    • These can be found in the world and provide a different number of slots.
19. Backpacks
    • Backpacks provide storage and can have multiple containers inside them.
20. Relief vests
    • The relief vest allows the synth character to retrieve ammo for the weapon. Only ammunition from the vest will be accessible for the weapons usually.
    • Ammunition that is too large and takes a longer time to reload is an exception to this.
21. Lower body armor
    • Pants.
22. Upper body armor
    • Body armor worn under relief and harness.
23. Left/right arm armor
    • Left/right arm armor or special extensions.
24. Coat
    • Clothes item worn on top of all other clothes.
25. Ladders
    • Ladders that can take player up and down.
    • While player is on a ladder, they cannot use the dominant hand item.
26. Item value categories
    • Items can be contemporary/common/relic/artifact/ancient.
    • This changes the strength of their effect, if they have one, and their price.
27. Repair items
    • Items that allow player to restore their weapon condition, item condition or HP.
28. Medical items
    • These items do not work on player, however they are highly valued by humans.
    • Unlike the usual, the placement of these items is realistic and they are considerably rare.
29. Ammo abundance
    • Some types of ammo are common and widely available.
    • Exotic ammo can be limited in quantity or might require additional resources to obtain.
    • Ammo can exist in damaged/outdated versions. Such ammo can degrade weapon condition faster or even damage it. Plus, it may have random ballistics.
    • Ammo can be picked up from the enemies.
    • Many of the mercenary outposts contain ammo caches.
    • There are also ancient and just old ammo caches still left to uncover all around the zone. Many of these caches provide poor outdated ammo in large quantities.
30. Individual magazines/clips
    • Each magazine is an individual object that must be loaded with individual bullet objects.
    • Reloading can be done automatically by a button press, taking some time.
    • Or can be done manually by dragging bullets into the magazine inside inventory.
    • A pattern can be specified for a magazine. Changing the pattern does not unload the magazine, allowing to combine them.
31. Elevators and moving platforms
    • These provide access to high areas or across large gaps, quickly.
32. Doors
    • Some doors can be opened and closed to separate environments.
    • Some doors are special and teleport player to an interior level.
    • Many doors are permanently shut to limit the scope of the world, however all spaces are implied to have a realistic scale.

Scripted Events and Locations

1. Scavenger camps
   • These act like quest hubs for human side quests and for the scavenger main quest line.
   • Scavenger faction is neutral to positive about player.
   • Humans offer a bigger variety of trading supplies at a higher cost.
2. Synth outposts
   • Synths prefer small scattered outposts rather than having central camps like humans do.
   • It is usually a source of synth-specific side quests.
   • Some of the outposts have a trader willing to engage with the player.
   • Synth traders tend to offer a small variety of items, however at a lower cost to the player.
3. Trading
   • Traders are available in scavenger camps, at synth outposts and sometimes randomly in the world.
   • Different traders provide items of a different kind, for different pricing.
   • Items are priced based on a category. Each trader has a specialty, a set of items they provide at a lesser cost than any other trader.
   • All traders can sometimes sell unique items.
4. Interiors
   • The interiors are separate worldspaces that are not affected by the outside world.
   • Some of the interiors are placed in the worldspace, however sparingly.
5. Crafting workbenches
   • There are crafting workbenches placed throughout the world. They allow to combine some items in order to obtain another.
   • These benches also allow player to repair weapons without repair items.

(to be expanded)

Primary Gameplay Loop

The primary loop is explore - cover - shoot. The player moves around complicated urban terrain, engaging human and creature enemies in tactical gunfights, managing their resources (maintaining weapons, keeping up with ammo counts, making sure equipment matches the enemies player is facing).

The game is influenced by S.T.A.L.K.E.R. series, Fallout: New Vegas and Arma 3. The primary activities in this game are:

1. Searching for technical artifacts
2. Interacting with NPC characters
3. Engaging in gunfights
4. Exploring the environment
5. Doing special narrative quests
6. Managing ammunition and supplies, weapon condition

→ Synesthesia Gameplay Systems and Elements