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Frequently Asked Questions

Answers to questions that are asked often.

Game Mechanics FAQs

Q: Is the game frame-locked? What frame reate is it designed to operate at?
A: The game is frame locked and whether it meets it's intended frame rate is a function of available processor and graphics resources. Internally, CPU-intensive tasks such as the Creeper Simulation is intended to run at 30 cycles per second. These tasks are also, where feasible, multi-threaded to take advantage of multiple processor cores. Display, the UI and rendering is frame-locked to the internal cycles at a 2x multiplier, thus yielding 60FPS for the player. Should game performance degrade due to to CPU intensive maps, then the player will experience a corresponding drop.

It is possible to have the simulation engine run at 2x and 4X speed, but this will not be reflected in the externally-observed FPS rate.

Q: The core game engine operates at 30 FPS (ideally, given sufficient processor resources) but the visual portion of the game is rendered at 60 FPS. How does that work?

A: Map panning, zooming, animation effects, and general other visual concerns looks smoother at 60fps. For instance, when you scroll the mouse wheel and zoom, the game animates the camera movement rather than snapping to new zoom levels. That animation looks better at 60fps. It also give an opportunity to do some things on the even frames and some on the odd. So things like shoving all of the creeper geometry changes to the GPU happen on the 'off' frames. Of course Unity still renders the creeper geometry every frame (which is at 60 fps ideally) so lighting and shadows and all of that happen at 60.

Q: * Why can packets no longer travel via units?

  • Why can I no longer use units to connect between towers as in CW3?

A: For pathfinding efficiency.

Pathfinding uses A* (and caching). There's a lot going on in the game, though, so pathfinding is just one straw on the camels back. So every little bit of efficiency here and there adds up. Removing terminal nodes from the graph (units) reduces the graph complexity by a lot (in most cases). It also produces a game play that I prefer (so it's a win win). Note that the graph changes frequently when people move 50 units at a time and there might be 100 packets per frame being emitted (from different sources to different destinations). So eliminating moving units from the graph makes that worse case scenario more efficient

To determine connectivity of any unit to the rift lab, a BFS (Breadth First Search) exploration of connected nodes is performed every frame. There are game rules based on knowing that… like the towers providing power. Since that happens anyway, the game keeps track of the distances when running BFS and then use that to determine the best route from the lab to a unit. As for the factory, a similar search is performed. The reason is because the one factory needs to receive and send to numerous destinations. The sources (deposits, etc) need to know if they are connected to the lab. So similar issue. Note there are some other optimizations in place. The BFS for the lab and the factory run in parallel each frame in their own threads. Some other cases exist where a packet needs to go places (like a pod). In cases where connectivity knowledge is needed, all units know if they were crawled in the BFS by the lab and the factory. So two thing are connected if they share a common connection. And of course A* is still there in the case of an arbitrary A to B routing need on the graph.

Note that these graph searches are performed every frame, are resource-intensive and area multi-tasked. This is also one of the primary reasons why non-network units (such as weapons) are not considered for packet routing in CW4.

Q: Describe the ““Hold” objective.
A: The Hold/survive objective will keep counting time so long as you hold the minimum number of bases (in this case 1, since there is only 1 on the map). The objective time is the minimum time, so you get the Hold objective when you reach that time. You can keep running the time up as long as you want… or can. Now in this mission, you can hold the mission as long as you care to once it is stable. One of the reasons I wanted to see your plays on this mission is I wanted to establish what seemed like an adequately long time to take over this type of map. What I'd like to do in other similar missions (in the full game) is add Creeper++ but with a really long initial time. After that, the map will more and more aggressive. Most people will have bugged out by then because most people will have one or more objectives already. For those that want to get the longest possible Hold time, that's when the challenge would begin. That's the idea anyway. For this map I think I'll make a setting on the Hold objective that says the min time is also the 'max' time. As in the Hold objective doesn't keep counting up past the specified time. That's the simpler scenario for maps that don't want to have some sort of ramp-up-to-eventual-destruction mechanic.



Q: Why do Cannons not shoot at the top of waves/visible creeper and instead aim at the terrain.
A: Cannons fire in a straight Line-of-Sight (Los) from the barrel to the terrain, limited by distance. There's no artificial rule about not being able to shoot higher. It just has to be able to 'see' the terrain it is firing at. So it can shoot up at a higher ledge, but it can't shoot at a terrain cell that is inland on higher terrain (since there is not line of sight to that cell)

From a game play perspective, firing part of the way up (into a wave, or at the top of a wave) has two impacts; It can miss more than you realize (because the creeper gets lowered before the shell arrives), and it's more computationally intense to calculate how high to shoot (or to try to predict what the height should be at some point in the future).

Somebody along the way mentioned that the cannon should shoot “as low as it can”. But that's fairly expensive to calculate too since it's a 3D line of sight calculation.

And the final reason… it works to shoot at the terrain. It's effective and the gameplay is fun.

From a lore perspective the cannon shell detonates on contact with the terrain.

Q: How do target acquisition work for cannons (and sprayers)?
A: Cannons in CW4 don't have have any other rule than “line of sight and max range”. So if there is a slope or a ledge, a cannon will shoot up at it. Normally, a cannon barrel sits just slightly lower than “1” off of the terrain it is sitting on. So it can't see on top of adjacent terrain that is 1 level higher than it is. It can see the edge, though. Nearby hills might have edges that hold creeper and the cannons can shoot at them. The old rules in CW3 were based not on LOS but on higher or lower. In CW3, it's just straight line LOS. Note that it is the map vertices that are evaluated.

The reason cannons can't just shoot at all lower terrain in range is… they'd be shooting through the terrain.



Q: How do target acquisition work for mortars?
A: Mortars use a simplified parabolic calculation for line of sight. It's simplified to a triangle. So it's two straight LOS calculations. For every point in range they check for LOS to a midpoint (at a height) and from the midpoint to the target.



Creeper/Wave Mechanics

Pre-release FAQs

Q: When will the game be released?
A: There is no planned release date. Historically, development of creeper world games take upwards of 3½ years or more.

Q: How much will the game cost?
A: A price has not been decided on. Expect pricing to be approximately in line with the previous games.

Q: Is there an Early Availability program, Kickstarter, Patreon, or other method that I can fund the developer or get early access to the game?
A: Virgil thanks you for your interest, but does not offer or take part in any such program. He strictly believes in selling a “finished good” at the time he feels it's ready for sale.

Q: Will the soundtrack for CW4 be released as DLC as per PF, or a free download as per CW3?
A: No decision has yet been made on the soundtrack. The availability of the soundtrack as DLC depends on the rights that Virgil obtains to distribute the music.

Q: Is there a beta program?

   When does the beta program start?
   How can I sign up  for the beta program?

A: Based on past experience, the feeling is that a beta program is most effective when the game is very near release. The selection process/criteria for the beta has not yet been decided on, but will most likely be from active, constructive community participation.

Q: Is there a demo program?
A: A demo will typically be available at the time of release

Q: I'm a proficient coder/artist/musician/awesome person, can I get a job?
A: Knuckle Cracker is intended to be a one-person development shop. Virgil does outsource artwork and music. For music, he already has preferred sources lined up and does not anticipate needing additional music. If you are a proficient artist with a body of work, you can provide samples of your work to Support at Knuckle for consideration. No decision is likely within the next 24 months or so.

Q: I have ideas that will revolutionize your game. Will you pay me?
A: Knuckle Cracker do not solicit ideas or contributions from outside parties. If you submit an idea, there is no obligation for anyone to consider it and it may be similar to work already underway. Regardless, no consideration, financial or otherwise, will be made for submitted ideas or suggestions.

Q: Will the game be available on Kongregate, Armor Games or other browser/Flash-based sites?
A: TL;DR: No,

The game is developed in Unity. Flash gaming is a thing of the past and the Unity Web Player is not supported anymore. Conversion to WebGL is problematic due to performance and storage constraints. So in all likelihood, only the stand-alone game will be available.

Q: Will the game be made available via Humble Bundle/GoG, or any sites other than Steam?
A: Typically, the game is available from Steam or from Other distributions sites will be evaluated from time-to-time. No definitive answer is available right now.

Q: Will CW4 make use of Steam Workshops or have it's own thing?
A: Virgil has not yet investigated the benefits that may accrue from using the Steam workshop. I believe he would be reluctant to implement a feature that would not be of use to those players obtaining the game from a different source than Steam.

Q: How do you make unit models in CW4?
A: The current models, which are only intended for testing and will not be the final models shipped in the game, are mostly made with Qubicle, but some are made with MagicaVoxel New link for MagicaVoxel is

Q: I hate the current unit models

   I love the current unit models.

A: the final unit models have not yet been decided on. When we have a line-up of units that will be “standard”, then Virgil may commission an artist to create a set of unit models. No decision has yet been made if unit models can be skinned, or if the current set will optionally be available for those keen on their look and feel.

Q: Will CW4 included a 3D model software to make custom units?
A: It is unlikely. It is more likely that it should be possible to import a popular 3D format model subject to constraints. This entire area has not yet been investigated for implementation.

Q: When we import CW3 maps into CW4, will the land textures automatically load too?
A: A decision on this has not yet been made.

Q: What is the maximum creeper per cell?
A: The Creeper representation has not changed between CW3 and CW4 (currently - this may change). It is internally represented as in integer value divided by 1,000,000. As such, maximum Creeper depth is 2147, after which it overflows and becomes anti-Creeper.

Visually, the creeper height is capped at a much lower level, for two primary reasons. 1. Units need to fly over it to not take damage. 2. on tough maps, with super-high-creeper, the camera must not be inside the creeper of have a view obscured by creeper. To this extent, the visual representation of the creeper displays the creeper as increasing density within the same height limitation.

A few other technical/performance limitations also determine this representation.

Q: Can we have caves, tunnels or bridges in the game?
A: TL;DR: No

Even though the rendering is in 3D, the underlying model has a 2-dimensional “surface on which creeper is modeled on top of terrain. There is no support for alternate layers of terrain and creeper. Such additional support will vastly increase the computational load and complexity of rendering and game play.

Q: Is height (z-axis) distance factored in to range calculations for firing and connections?
A: Yes, the distance is calculated factoring in different heights and also line-of-sight. This means that often a tower on very high terrain cannot connect to a nearby tower on lower terrain. Or that two towers cannot connect if there is a high piece of terrain between them.

Q: Is a CRPL to 4RPL converter something Knuckle Cracker will implement?
A: Unlikely, for the simple reason that many of the commands may not be similar.

Q: Will CW4 allow mappers to upload their own custom sound effects (<10s)?
A: While there has been no consideration made for sound effects in CW4, it is unlikely that the stance on inducing external sounds will change from the position adopted in previous games - ie. No.


cw4/frequently_asked_questions.txt · Last modified: 2020/09/17 09:53 by Karsten75