[Naval] Bow wave effect improvements

[Dese_Tsuterikka]

Would you like to see improved bow waves in-game?

• Yes
• No

Bow Waves

Good day! This suggestion will go through various visual improvements that could be brought to the bow waves present on vessels as they move on water.
Bow waves are a prominent sight on moving vessels, and arise due to ships displacing water, and the energy transfer to the water body.
Having good looking bow waves could greatly enhance the visual experience of naval battles.

Problems of current implementation:

• The looks of bow waves

  • They look passable on some of the smaller destroyers.
  • On most ships, they simply look like a ball of splashes covering a tiny portion of the bow. They look far worse on slower ships with high freeboards, such as dreadnoughts.
  • They can look exaggerated on coastal vessels, such as sub-chasers and minesweepers.
  • A common complaint is that ships look like cardboard cutout moving across the water.

• Only the player’s ship and (sometimes) AI ships display bow waves in game.
  In replays, only the selected player gets a bow wave.

  • In screenshots and videos with multiple player ships, having only one ship with a bow wave effects sticks out like a sore thumb.
    
    
    
    Only the Emile Bertin (foreground) has a bow wave, the Haguro (background) doesn’t

• There is a sort of bow wave effect in-game that uses displacement and a wake texture, but it lacks the dynamism of proper bow waves and also can generate some sharp spikes on lower displacement settings. It could be converted to Kelvin wakes or kept as is.

Proposed changes:

• Have the bow waves be displayed for all vessels, both in matches and in replays.
  
  All vessels should have their bow waves rendered

• Form a contour/spline for the bow wave (The white spray).

  • In real life, the contour would change shape and length depending on speed and draught, and waterline entrance angle.
    A simple implementation would be a damped wave/exponentially decaying sinusoidal wave.
    A more complicated approach would take into account the aforementioned parameters (see end).

    • The flow and the contour/white spray should get thicker and more turbulent as the wave moves along the bow, similarly to how boundary layers form.

    • The contour should preferably be 3 dimensional and curl as it progresses along, so as to have some vorticity. It would turn over near the bow crest before crashing back into the sea.
      

  • Ships with low waterline entrance angles/slender bows would create a smooth overturning bow wave in calm waters.

  • Ships with fuller waterlines/high entrance angles would create more turbulent bow waves.

  • Some small fluctuations should be added make it more dynamic.

  • The contour of the bow wave would have a white color and the area connecting the contour to the waterplane would be translucent.
    

    

  • Earlier in Naval’s life, the bow waves were very good looking. They had accurate contours and coloring (Particularly suitable for calmer waters).
    This can serve as a good reference as to what they can look like.
    

• “Rooster tails”, the water rise at the stern of the ship due to the propellers, could also be added.

• Kelvin wakes:
  

  
  
  Once again, in earlier versions of War Thunder, the waves and wakes produced by vessels were quite different. They were made to look like “Kelvin wakes”, which have a distinct curved vee shape.
  It could be explored whether adding back this feature for the appropriate conditions can be done, as it would complement the proposed bow waves quite well. It would be most appropriate for calm waters.
  
  
  
  Here, Suzuya shows both Kelvin wakes and overturning bow waves

TL;DR :

With these changes, vessels would look more dynamic and look less like cardboard cutouts.
This would make the game more enjoyable to look at.

On top of that, estimating ship speeds can also be done through bow waves, and could help with gunnery.

Figure shows location of wave nodes from bow stem for various speeds. Using bow waves is a common method of estimating a ship’s speed.

Notes:
“Simple analytical relations for ship bow waves” and “Ship bow waves” by Francis Noblesse et al provide ways to accurately model bow waves based on simply parameters such as draft, waterline entrance angle etc. . . This can provide a reference should the waves be desired to be modeled this way.

Gallery

Some crudely made screenshot edits:

Thank you for reading ! Please do vote on whether or not you would like to see this implemented.