Dev Diary #19: Concealment, Detection, and Lines of Sight
The best protection against any weapon is not being seen in the first place. In MENACE, players and enemies have a lot of tools and tactics to avoid being seen or detected by the enemy and shape the battle in their favour.
Let’s dive in:
[h2]Vision Range[/h2][hr][/hr]The basis for any ranged combat system is, of course, the vision range of combat units. This is set at around nine tiles for most infantry, but this is not set in stone. This is the tile range on which the fog of war is lifted, and an enemy or neutral unit is revealed, which can thus be shot at.
Vehicles usually have a lower vision range despite most of them having electronic optics that enhance the driver's vision. The use of these devices is just slower and more cumbersome than being out in the open and looking around. Also, it reduces situational awareness, and that is why some especially heavy vehicles will have a minimum view range. An enemy unit standing right behind a tank might be invisible to the crew as it is too close and at a lower angle. In general, walkers will have more situational awareness than tanks as they can turn more quickly, are higher, and more mobile.
[h2]Lines of Sight[/h2][hr][/hr]Now it gets a bit controversial as the lines of sight rules in MENACE are different from many other games. Due to the larger scope of the game and the squad-based nature of units, we realized early in development that we would have to make some compromises and abstractions when calculating lines of sight.
The guiding principle here was to have a system that has maximum predictability for players and not necessarily maximum realism. Players not being able to accurately predict from what point of the battlefield they can see and shoot at an enemy, or at what point they are safe from enemy fire, leads to big misplays, massive frustration, and can easily cost you a mission.
That is why we decided to have 1x1 tile obstacles as well as 1x2 obstacles, not block lines of sight or lines of fire. Any obstacle that is 3x3 or bigger will use raycasting between tiles to determine if a tile is visible or not, and completely block any line of sight or fire.
As the line-of-sight-blocking obstacles are easily identifiable, players have a clear understanding of vision lines on the battlefield and can use them effectively.
When a squad is taking cover behind a 1x1 building, we can assume that they are pressing up against the wall but are still bending around corners to see and shoot. This is not visually modeled in the game animations, but it explains why units can still see and shoot from behind these objects.
Of course, standing next to any object grants directional cover and “concealment,” so it is still crucially important to keep your troops in cover.
[h2]Detection Versus Concealment[/h2][hr][/hr]Determining if a unit is within vision range of another unit is only the basis of determining if it is actually visible. We do have two factors from opposing sides that influence the final outcome.
Firstly, we are looking at concealment. Concealment depends on the characteristics and the position in the environment of the target unit. Each point of concealment reduces the effective vision range of all enemies against this particular unit. So if a unit is standing 9 tiles away from an enemy, it is visible. Still, if it has 1 point of concealment, this reduces the effective vision of that enemy by 1 down to 8, making the unit invisible. Another enemy standing closer by will, of course, still see that unit.
Concealment is gained through different means. Units might have promotions (perks) or accessories that increase their concealment. One example is infiltrator armor, which increases concealment, and another is a camouflage kit, which also increases concealment.
The environment itself is the main concealment mechanic, though. A unit in cover automatically gains concealment depending on the type of cover it is using.
Terrain features like high grass that units can move into are even more effective for hiding. Finally, some objects can contain units, like a dense forest or a bunker, both of which increase concealment.
An opponent's detection stat reduces the concealment of a unit. This stat can also change based on promotions or equipment like thermal vision devices and others. The detection is deducted from the enemy’s concealment when determining if a unit is visible or not. A detection of 1 versus a concealment of 1 will simply cancel out.
Example:
A Marine squad is hiding in tall grass, 9 tiles away from a Pirate unit. The grass provides +1 concealment, and the Marines are wearing infiltrator armor for an additional +1. The Pirate unit has no detection bonuses.
In the game, we have a UI overlay that highlights exactly on which tiles an enemy will see you based on the concealment of your unit and that tile. This enables players to actually play around with the mechanic and not move somewhere and hope for the best.
We also decided to use a deterministic detection system rather than a random or chance-based one. Having it be chance-based will introduce too much uncertainty and randomness that is not easy for players to understand. In turn, this might lead to players ignoring the mechanic altogether, as it just sets them up for miscalculations and misplays.
[h2]Shooting and Visibility[/h2][hr][/hr]When a concealed unit is shooting any of its weapons, it will automatically be revealed to the enemy, no matter how high its concealment is. It will vanish again at the end of its turn, but the AI does remember where it last saw a unit and will move towards that position or just blind fire there.
The exception to this is silenced weapons, which do exist but are rather hard to acquire. They come with modded weapon variants and will not come as separate accessories. A unit with a silenced weapon will not be revealed to the enemy when shooting from concealment.
Example:
A Scout unit with high concealment is positioned in a forest tile, 8 tiles from an enemy tank. The Scout is equipped with a regular anti-vehicle rocket launcher.
So, before you reveal your hiding place by shooting from concealment, you have to make sure you are in the best possible position. Or it might be better to hold your fire until the enemy moves into an even better ambush position.
[h2]Engage, Explore, and Stay Informed[/h2][hr][/hr]That's it for now! We'll see you next Friday.
You can find us on Discord, BlueSky, Twitter, YouTube, Facebook, and Reddit for discussions, updates, and feedback. You can also subscribe to our monthly MENACE newsletter on our website — just scroll to the bottom of the page to sign up.
https://store.steampowered.com/app/2432860/MENACE/
And here are the recent prior Dev Diaries in case you've missed them:
https://steamcommunity.com/games/2432860/announcements/detail/515208181997109524
https://steamcommunity.com/games/2432860/announcements/detail/515207543396499582
https://steamcommunity.com/games/2432860/announcements/detail/642433677808108044
Let’s dive in:
[h2]Vision Range[/h2][hr][/hr]The basis for any ranged combat system is, of course, the vision range of combat units. This is set at around nine tiles for most infantry, but this is not set in stone. This is the tile range on which the fog of war is lifted, and an enemy or neutral unit is revealed, which can thus be shot at.
Vehicles usually have a lower vision range despite most of them having electronic optics that enhance the driver's vision. The use of these devices is just slower and more cumbersome than being out in the open and looking around. Also, it reduces situational awareness, and that is why some especially heavy vehicles will have a minimum view range. An enemy unit standing right behind a tank might be invisible to the crew as it is too close and at a lower angle. In general, walkers will have more situational awareness than tanks as they can turn more quickly, are higher, and more mobile.
Unit Type
Vision Range
Notes
Infantry
~9 tiles
Baseline visibility for most combat situations
Vehicles
Lower than infantry
Reduced awareness; may have blind spots behind and below
Walkers
Higher than vehicles
Better mobility and situational awareness due to height
[h2]Lines of Sight[/h2][hr][/hr]Now it gets a bit controversial as the lines of sight rules in MENACE are different from many other games. Due to the larger scope of the game and the squad-based nature of units, we realized early in development that we would have to make some compromises and abstractions when calculating lines of sight.
The guiding principle here was to have a system that has maximum predictability for players and not necessarily maximum realism. Players not being able to accurately predict from what point of the battlefield they can see and shoot at an enemy, or at what point they are safe from enemy fire, leads to big misplays, massive frustration, and can easily cost you a mission.
That is why we decided to have 1x1 tile obstacles as well as 1x2 obstacles, not block lines of sight or lines of fire. Any obstacle that is 3x3 or bigger will use raycasting between tiles to determine if a tile is visible or not, and completely block any line of sight or fire.
Obstacle Size
Blocks Line of Sight?
Notes
1x1
No
Units can see/shoot around these
1x2
No
Treated the same as 1x1 for visibility
3x3 or larger
Yes
Blocks vision and fire; uses raycasting
As the line-of-sight-blocking obstacles are easily identifiable, players have a clear understanding of vision lines on the battlefield and can use them effectively.
When a squad is taking cover behind a 1x1 building, we can assume that they are pressing up against the wall but are still bending around corners to see and shoot. This is not visually modeled in the game animations, but it explains why units can still see and shoot from behind these objects.
Of course, standing next to any object grants directional cover and “concealment,” so it is still crucially important to keep your troops in cover.
[h2]Detection Versus Concealment[/h2][hr][/hr]Determining if a unit is within vision range of another unit is only the basis of determining if it is actually visible. We do have two factors from opposing sides that influence the final outcome.
Firstly, we are looking at concealment. Concealment depends on the characteristics and the position in the environment of the target unit. Each point of concealment reduces the effective vision range of all enemies against this particular unit. So if a unit is standing 9 tiles away from an enemy, it is visible. Still, if it has 1 point of concealment, this reduces the effective vision of that enemy by 1 down to 8, making the unit invisible. Another enemy standing closer by will, of course, still see that unit.
Concealment is gained through different means. Units might have promotions (perks) or accessories that increase their concealment. One example is infiltrator armor, which increases concealment, and another is a camouflage kit, which also increases concealment.
The environment itself is the main concealment mechanic, though. A unit in cover automatically gains concealment depending on the type of cover it is using.
Terrain features like high grass that units can move into are even more effective for hiding. Finally, some objects can contain units, like a dense forest or a bunker, both of which increase concealment.
An opponent's detection stat reduces the concealment of a unit. This stat can also change based on promotions or equipment like thermal vision devices and others. The detection is deducted from the enemy’s concealment when determining if a unit is visible or not. A detection of 1 versus a concealment of 1 will simply cancel out.
Example:
A Marine squad is hiding in tall grass, 9 tiles away from a Pirate unit. The grass provides +1 concealment, and the Marines are wearing infiltrator armor for an additional +1. The Pirate unit has no detection bonuses.
- Total concealment: 2
- Pirate detection: 0
- Effective vision range: 9 - 2 = 7 tiles
In the game, we have a UI overlay that highlights exactly on which tiles an enemy will see you based on the concealment of your unit and that tile. This enables players to actually play around with the mechanic and not move somewhere and hope for the best.
We also decided to use a deterministic detection system rather than a random or chance-based one. Having it be chance-based will introduce too much uncertainty and randomness that is not easy for players to understand. In turn, this might lead to players ignoring the mechanic altogether, as it just sets them up for miscalculations and misplays.
[h2]Shooting and Visibility[/h2][hr][/hr]When a concealed unit is shooting any of its weapons, it will automatically be revealed to the enemy, no matter how high its concealment is. It will vanish again at the end of its turn, but the AI does remember where it last saw a unit and will move towards that position or just blind fire there.
The exception to this is silenced weapons, which do exist but are rather hard to acquire. They come with modded weapon variants and will not come as separate accessories. A unit with a silenced weapon will not be revealed to the enemy when shooting from concealment.
Example:A Scout unit with high concealment is positioned in a forest tile, 8 tiles from an enemy tank. The Scout is equipped with a regular anti-vehicle rocket launcher.
- Before shooting: The Scout is concealed due to terrain and perks. The tank does not detect them.
- Upon firing: The Scout immediately becomes visible to all nearby enemies, including the tank.
- After firing: The Scout returns to concealment at the end of the turn, but the AI still remembers the shot’s origin and may send units or fire at that tile.
- Same Scout, but now equipped with a silenced modded rifle.
- The Scout fires from concealment.
- The unit remains hidden. The enemy never detects the shot’s source.
So, before you reveal your hiding place by shooting from concealment, you have to make sure you are in the best possible position. Or it might be better to hold your fire until the enemy moves into an even better ambush position.
[h2]Engage, Explore, and Stay Informed[/h2][hr][/hr]That's it for now! We'll see you next Friday.
You can find us on Discord, BlueSky, Twitter, YouTube, Facebook, and Reddit for discussions, updates, and feedback. You can also subscribe to our monthly MENACE newsletter on our website — just scroll to the bottom of the page to sign up.
https://store.steampowered.com/app/2432860/MENACE/
And here are the recent prior Dev Diaries in case you've missed them:
https://steamcommunity.com/games/2432860/announcements/detail/515208181997109524
https://steamcommunity.com/games/2432860/announcements/detail/515207543396499582
https://steamcommunity.com/games/2432860/announcements/detail/642433677808108044