Fantastic game, but one serious issue

[kentsfield]

Hey, I'm mostly new here so let me start out by saying great work! You have a nifty little game here that I have been enjoying very much. It's not without its flaws, as was also the case with the original, but most are easily overlooked. There is one glaring issue however, which is severely hampering my enjoyment: line of sight.

The problem with the line of sight mechanic, as far as I can tell, is that the line seems to be determined using grid-based movement rather than a linear path. The result is that bullets travel in a zigzag, rather than a straight line as one would expect them to. This is quite jarring and leads to some oddities, including:

• Shots tend to clip objects that they wouldn't normally (one of the reasons clear shots at med-long range are so rare)
  
• Bullets have the ability to "curve" around corners
  
• Narrow-angle shots (such as shooting through windows) tend to be a lot more fruitful than they probably should be
  

All of this is problematic because it creates a disconnect between what the player expects to happen based on the visual data he is given and what actually occurs. At best, the player simply doesn't notice or raises his eyebrow, but at worst this can mean the unexpected death of a solider or even a mission failure. Such was the case for myself earlier today, when one of my prized soldiers bit the dust after being shot through a corner that the game had given no reason to think was unsafe. I was really into the mission (and my campaign) up until that point, but the event really robbed me of my desire to keep playing, and I fear that this will be a regular thing if not fixed.

The fix seems simple (and as I have little knowledge of programming I use the term "simple" loosely): calculate line of sight with a straight line from the sprite to the target, rather than with grid-based movement.

In closing, I hope this fix is possible and will be implemented in the future. If there is already a mod that addresses this, please point me in that direction. Thank you for taking the time to read my post, and thanks for making this great game!

[kentsfield]

Here's an example from a session I just played:

As soon as I clicked end turn, the pictured alien, from the exact position he's in, turned and fired through the window toward my ship, and killed the xenonaut inside. I sat there for a few seconds, marveling at the absurdity. How am I supposed to make decisions with any sort of tactical sense when such outlandish things are possible?

[SyDaemon]

Sounds like providing the saved game would help.

[Dandywalken]

I've had the same happen OP, and I honestly think it may just be particular tiles operating improperly in terms of LoS blockage for incoming/outgoing sight. Its most certainly an issue though

[kentsfield]

Sounds like providing the saved game would help.

This was from an Ironman playthrough, unfortunately. I originally took the screenshot for another reason: if you'll notice, vision of the alien is being granted by the selected xenonaut, who has no line of sight of the alien. Unless that particular xenonaut has the gift of x-ray vision, I have no idea why I'm able to see the alien. This seems to happen a lot, too. Maybe I just don't understand how line of sight works, but regardless, it's not very intuitive.

Anywho, I don't mean to sound negative as I'm really enjoying the game otherwise, but it is very frustrating to be digging a session and then have it ruined by something like the above example happening. Really hope this can be fixed at some point.

[Gauddlike]

Remember that all of the 2D objects in the game are just a sprite with a few basic settings to the 2D engine.

It doesn't have the physical view of the object that the player does or that would be possible in a 3D engine.

To the game engine there is no real difference between a window with a 25% stopping chance and a signpost with a 25% stopping chance, even though to the player they appear to cover completely different sections of the tile they occupy.

There is no solid 3D object there to draw a line past to determine if there is a direct line of fire.

For example a tree stump can block shots that would appear to pass by on either side of the actual stump because the whole tile has an equal stopping chance.

The engine just knows that the tile at x28,y45 has a 25% chance of stopping a shot that passes through it.

It does not know, and cannot know, that the stopping chance should only apply to the part covered by the sprite the player can see and not apply to those parts of the sprite that are transparent.

Even if the system was rewritten to use a direct line drawn between two points rather than tile to tile that problem would still prevent the player from eyeballing shots as they would look in a 3D system.

The game engine was a poor choice from an early coder (who later left the team) which was not found to be a poor choice until too late in development to throw all of their work out and start again.

[kentsfield]

The engine just knows that the tile at x28,y45 has a 25% chance of stopping a shot that passes through it.

It does not know, and cannot know, that the stopping chance should only apply to the part covered by the sprite the player can see and not apply to those parts of the sprite that are transparent.

Thank you for your reply. That's unfortunate, but I suspected as much. Truthfully, shots being penalized because they clip any part of the tile isn't a huge deal. It seems to be consistent, so that knowledge can be reliably factored into decision making.

What still doesn't make sense to me is the "magic bullet" shots that appear to change direction mid trajectory and/or curve around corners, like my example above. Even without the ability to draw a straight line between two tiles surely there must be a better way to implement this. It's starting to feel like standing around a corner or anywhere near a door/window is more dangerous than standing out in the open.

Edited June 22, 2014 by kentsfield

[Gauddlike]

It does look odd at times and I agree that the line of sight near corners is still wonky.

The code that is supposed to represent corner leaning and the oddness of shot path tracing having to use the little sub tiles does combine to give some weird and (not so) wonderful effects.

Edited June 22, 2014 by Gauddlike

[Chris]

I wouldn't be surprised if that specific issue was a mis-set tile. I can't see why you should have direct LOS (the red icon) with the selected soldier either.

[Gauddlike]

If the window has no stopping chance because of the glass breaking thing then the roof of the chinook would have to be invisible to line of fire for that shot to work.

[PurpleXVI]

If the window has no stopping chance because of the glass breaking thing then the roof of the chinook would have to be invisible to line of fire for that shot to work.

Roofs and height in general seem to be pretty wonky with regards to LoS/clear lines of fire. I often seem to find that I can hit enemies on rooftops with clear shots even though I should only see a tiny bit of their heads over the edge of the roof, and conversely that soldiers on top of buildings can't throw grenades for beans nor hit jack down below.

[crusherven]

I find that oftentimes I can see up into the second floor of a UFO, as well. It might have something to do with elevation or floors.

[Phier]

The cover system is quite frustrating. I have a "clear" shot by the tiles but its 100% blocked, then again the alien can fire from it and bulleye my guy no problem. It makes it very hard to be strategic in selecting spots to hide behind. My kingdom for some sort of LOS tool.

[guto8797]

Yes, Shame this is an engine issue, cover is terrible ATM. You have 100% block. aliens bullseye you. Get to a corner, can't hit alien. Alien shoots trough wall. The thing is that with this system whe don't know where we can shoot from, the AI does. I hope there is something doable about this, either AI and player having the same restrictions and/or making these borders clear.

[cybrbeast]

I wonder if it would be possible for the game to display places a selected soldier can reach in his turn that have a clear LoS towards an alien. Maybe by illuminating tiles, with green being clear LoS, yellow 50% block, red 100% blocked, or something like that. Would be nice if you could trigger a display like this with the Alt key for example. This would help enormously, because currently I've quite often wasted a lot of TUs or a turn by incrementally moving my soldier to see if I can get to a spot with LoS.

Probably hard to implement or mod, but I do think it would really add a lot to the gameplay.

[Fucille]

Adding to this, I've had issues where my xenonauts get line of sight on an alien in the second floor of a landing ship from outside, but are unable to shoot them. Said aliens however, have no difficulty shooting down through the walls of their shit.