The visibility system in World of Warplanes is the complex mechanic that determines what you see and what you don’t in the game. This is particularly important in regards to enemy planes and ground targets. The visibility system is based on ray tracing technology that’s included in the BigWorld-engine we use for our game. In this post we’ll unveil some of the details about how this system works and how you can use it to gain tactical advantage in battle.
The visibility system defines two factors: how far the “hunting” plane “sees” and how effectively the “prey” is camouflaged. We’ll use the “hunter” and “prey” terms further for the sake of easier understanding of how these two factors affect each other.
The viewing range is defined by:
- Viewing sectors that go out from the center of the aircraft in various directions and have conical or spherical shapes. The longest viewing sector for all aircraft is facing forward. The upward-facing hemisphere that is inclined at an angle of 45° provides detection above the plane and to the sides. It is around 1.5 times shorter than the reach of the frontal viewing sector. Two-seat aircraft also have a backward-facing viewing sector that represent the rear gunner’s view. And finally, there is a special, circle-round sphere around the aircraft that provides guaranteed detection of any enemy aircraft. Whatever enters this sphere will be automatically detected, regardless of its directional positioning in relation to your aircraft. That way, the designers made sure that you couldn’t be attacked at close range without knowing where the fire is coming from. The shape and range of these viewing sectors is based on multiple factors – game balance considerations, capabilities of our current game engine and also on historical data about the view quality from the real aircraft cockpits of the corresponding, historical plane.
To illustrate everything you’ve just read, let’s take a look at these sectors:
Here you can see the viewing ranges for each aircraft type, split by the aforementioned viewing sectors:
Now let’s take a look at the camouflage mechanics. There are a set of factors that can reduce the effectiveness of a hunter’s plane’s detection capabilities (meaning that a camouflaged “prey” will not be detected even after entering the enemy’s viewing sector range). These factors are:
- Altitude camouflage: an aircraft flying at 200 meters or less gets a gradually increasing bonus to camouflage. The lower you’re flying – the less visible to enemy planes you are. Maximum bonus values are achieved at 50 meters and less. Different aircraft classes have different altitude camouflage coefficients. Attack Aircraft are the most effective ones for hiding in plain sight: their visibility drops almost by half when flying within the required altitude parameters.
Here’s a less known fact for you: the altitude camouflage stops working if there’s an enemy aircraft flying within 200m over the “prey”. But it stops working only for this exact enemy – if there is another “hunter” outside the 200 meter proximity range – the “prey’s” altitude camouflage will continue affecting that outside hunter’s detection value.
- Adaptive camouflage: every map type (desert, marine, summer and winter) has a corresponding paint scheme that you can apply to your aircraft which gives you a 15% boost to camouflage under all circumstances. As you can imagine, this is especially important for Attack Aircraft.
- Aircraft visibility coefficient: every class and tier, and even some specific machines, have different values that define when it will be detected by a specific enemy (whether it’s at a longer or shorter distance than usual). For example, slow-flying biplanes of the starting tiers have low visibility coefficients, while jet-powered top tiers have higher ones. This means that, for example, a Tier IV piston fighter would be able to detect a Tier VI one at a greater distance while staying invisible due to boosts to viewing range and camouflage, even though they both have 2250 meters long forward-facing sectors.
- Clouds and fog: This mechanics uses a quite sophisticated algorithm that’s based on ray tracing technology. All the clouds consist of voxels – volumetric objects with a specified size that have a transparence characteristic that defines their opacity. The line of sight that’s coming from an aircraft is multiplied with the opacity coefficient of every voxel that it has to pass through to get to the “prey”. The larger and denser the cloud, the more your viewing range shortens. The system itself and cloud locations are tuned in such a way that even in the worst case scenario (a wounded pilot, short viewing sector and inside a dense cloud) you will still be able to detect an enemy before he comes into effective firing distance, so that you still can evade the attack.
- Sun blinding mechanics: If the angle between your view at a target and the sun or moon location on the map is within a special alpha parameter, the target’s visibility will be decreased to reflect the light source blinding your pilot. If the target and the sun are aligned – the blinding is the strongest, and, as the alpha angle increases with shifting perspective, the blinding decreases. Alpha angle and blinding strength depend on the particular map that you’re playing on. On some maps the sun or moon shine stronger or are positioned higher. On other maps again, their effect is less noticeable. The maximum viewing range drop due to sun blinding is 70%. The effect of sun blinding can also be blocked/reduced by the clouds – this mechanic uses the same principle as the viewing range reduction: the rays of sun lose some of their intensity as they pass through clouds or fog.
And, finally, there are also some mechanics that decrease camouflage effectiveness:
- Shooting: Firing from forward-facing armament, rear turrets or launching rockets neutralises altitude camouflage. In the future, it is also planned to have it neutralise cloud and fog camouflage. So if you’re trying to avoid detection – try to hold your fire. The only exception are bombs – dropping bombs will not decrease your camouflage levels. However, keep in mind that, if the explosion does not destroy but rather only damages the target, the report of this will show up on the mini-map.
- The state of your plane: the more damaged your aircraft is, the denser the smoke that you usually drag behind you. The more smoke you carry, the more visible you are. When your plane catches fire, or when your engine is destroyed, altitude- and cloud camouflage stop working completely. The ‘Pneumatic Restarter’ consumable can help you restore the engine and camouflage at the same time (though visually your plane will continue smoking).
All of these mechanics and parameters are fine-tuned with two gameplay aspects in mind. On the one hand, players have a way to hide from the enemy and find a covert route to their target. Simply put, if you use the camouflage mechanics well, you can come up with a good tactic that can be advantageous for the course of your battle. For example, we often see how experienced teams that participate in tournaments use clouds to ambush their opponents or to fly to a certain flank to enter the battle from the sun-lit side to catch their opponents unawares. On a more basic level, the visibility system is meant to enable comfortable gameplay. For example, the guaranteed detection range is a feature that’s meant to help you deal with opponents that are in your immediate surroundings.
Let’s take a look at some typical tactical moves that you can use based on this knowledge.
- Naturally the aircraft class that benefits most from camouflage are Attack Aircraft. Usage of altitude camouflage and paint schemes is a must for them, since their other defensive capabilities (survivability and rear gunner) won’t help much if a sole Ilyushin is detected by a bunch of enemy fighters. When the battle starts, you should always “hug the ground” on your way to the target. If you do it right, more often than not, a fighter won’t detect you even when flying directly above. Avoid firing before you’re ready to attack the target effectively – otherwise you’ll lose camouflage before you’re in range where you can deal the biggest amount of damage. Also, we’d like to point out (even though it’s not related to the visibility system) that you should avoid attacking a ground target, until you see from the mini-map that enemy fighters are already engaged in a dogfight.
- Using the visibility system, Fighters can evade pursuit by flying into a cloud or in the direction of the sun. When the enemy can’t see you, he can’t shoot at you. That’s why, actually, we don’t recommend using client mods that disable clouds or fog. If you have them installed, you can’t know where to hide or where an ambush might be coming from next.
- When you’re searching for a low-flying Attack Aircraft close to the ground, remember: your plane’s viewing range is the shortest faced downward. That’s why a good method to extend your viewing capabilities would be to either fly inverted or do an ‘Aileron Roll’ by holding A or D (on default mapping). The same rules apply for scouting at the start of the battle. After several rounds you’ll know from which direction you should expect the first enemies to appear. Naturally, if you turn your aircraft’s nose into the proper direction, you’ll detect them sooner.
- Another interesting tactical move that you might try is what MMORPG players call “agro-ing”. Essentially, this means drawing an enemy’s attention to one player and lure him into a trap. Approach the direction where the first detection usually happens and start shooting. Camouflage will be disabled and you’ll become visible. Then use boost and get back to safety amidst your allies. More often than not, enemies will congregate towards the spot on the map where an enemy first popped up – so “agro-ing” an enemy team can give you an opportunity to lead them to a place where engaging them is advantageous for you or your teammates. You can also use this technique to distract the enemy team from a flank where your allied Attack Aircraft are creeping up on unprotected ground targets.
In conclusion we’ll just say that World of Warplanes features a lot of mechanics that allow players to win in an unusual fashion. If you put some thought behind it and be creative, you can always gain an advantage on the opposing team.