DUST Search - Sticky:How things work: Dispersion

J4yne C0bb wrote:

First of all, thanks very much, I enjoyed the read.

CCP Logibro wrote:

Most rifles have this set to 0, meaning that they have no dispersion when looking down the weaponGÇÖs sights. The HMG has this set to 1, which means that it has the same dispersion when zoomed as when aiming from the hip.

Lastly, we have the state multipliers. There are separate multipliers for the decay rate, growth per shot maximum and minimum depending which of four different states you are in: Crouched, moving, sprinting and zoomed. These allow you add things like bonuses for crouching or increase your dispersion after just finishing sprinting. To go along with these state multipliers we have GÇ£Growth Rate Below MinimumGÇ¥, which increases your dispersion by a certain amount per second when itGÇÖs below the minimum dispersion. An example of this would be if you start sprinting, your dispersion will increase to the new minimum based on the minimum sprinting state multiplier (which for the Assault Rifle is x5, or 3.75 degrees) at a speed of 3 degrees per second. Decaying from a dispersion value above your current maximum dispersion occurs at the normal dispersion decay rate.

Very interesting. So if I'm interpreting correctly, zooming in on far-off targets with the HMG to try and decrease dispersion has absolutely no effect, other than whatever benefit is gained in order to track the enemy in your reticle? I ask because ADSing with the HMG has a slightly longer animation than with other weapons, and being in ADS has a detrimental effect on your peripheral vision -- I'm sure I've died more than once because of that.

Also, since I'm always running as a fatboy, I should refrain running over to enemy heavies and start blasting -- whenever possible, I should let that dude come to me instead?


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CCP Logibro C C P C C P Alliance 9390	Posted - 2014.10.07 18:19:00 - [1] - Quote Hello wonderful forum readers. Today is the first in what may (depending on how much you like it and how much time I have) be a series of posts on how some of the mechanics of DUST actually work. These include things like how is damage done calculated, how heat works and today's topic: Dispersion. So what is dispersion? Dispersion is what causes your bullets to fire in a cone from the center of your weapon, rather than all coming out as a straight line. This is generally more obvious with faster firing weapons (with the HMG being a prime example). So how does it work? First off, not every weapon actually uses dispersion. A good example of this is the Laser Rifle. Additionally, any weapon that fires a projectile completely ignores dispersion. Next (assuming our weapon is using dispersion) we have the maximum and minimum dispersion. These two numbers dictate what the maximum and minimum possible dispersion numbers you can achieve on your weapon are. Both are specified in degrees from origin (the exact point that you're aiming at in the middle of your crosshair). For example, the Assault Rifle has a maximum dispersion of 3 degrees, and a minimum of 0.75 degrees. This means that when firing you start with 0.75 degrees of dispersion, and will gradually grow to 3 degrees of dispersion. Next we have growth per shot. This number specifies how much the dispersion should grow (in degrees) every time you shoot the weapon. For the Assault Rifle, this is 0.27 degrees. So using what we know, firing our Assault Rifle for one second should increase our dispersion by 3.6 degrees (0.27/0.075) right? As it turns out, thatGÇÖs not the case. We also have dispersion decay. This is the rate that dispersion is moving back towards its minimum value. Your dispersion is decaying at all times, even when you are firing. However, dispersion decay isnGÇÖt a flat number like dispersion growth is. Instead, we have a GÇ£Decay Rate at Maximum [Dispersion] per SecondGÇ¥ and a GÇ£Decay Rate at Minimum [Dispersion] per SecondGÇ¥. For the Assault Rifle, these two numbers are 6 degrees and 2.5 degrees respectively. So how do we use these two numbers? The dispersion decay rate increases from its minimum to its maximum as the dispersion increases from its minimum. This means that as you get closer to maximum dispersion, your rate of decay increases. Using the Assault Rifle as an example, if our current dispersion is 1 degree, then our rate of dispersion decay is around 2.8 degrees per second. If our current dispersion is 1.2, then our rate of decay is about 3.2 degrees per second. When combined with our growth per shot, this serves to slowly bring our rate of dispersion growth as our dispersion gets higher. You can see examples for a number of different weapons in this sheet. If you look at the attached chart, you might also notice something strange: one of the lines is decreasing. That would be the HMG which is unique in that it has inverse dispersion. What this means is that the more it fires, the more accurate it gets. There are also some other numbers that affect dispersion we havenGÇÖt gone over yet. The first is the Zoomed Dispersion Multiplier. This increases or decreases the dispersion when looking down the sights of a weapon. Most rifles have this set to 0, meaning that they have no dispersion when looking down the weaponGÇÖs sights. The HMG has this set to 1, which means that it has the same dispersion when zoomed as when aiming from the hip. Lastly, we have the state multipliers. There are separate multipliers for the decay rate, growth per shot maximum and minimum depending which of four different states you are in: Crouched, moving, sprinting and zoomed. These allow you add things like bonuses for crouching or increase your dispersion after just finishing sprinting. To go along with these state multipliers we have GÇ£Growth Rate Below MinimumGÇ¥, which increases your dispersion by a certain amount per second when itGÇÖs below the minimum dispersion. An example of this would be if you start sprinting, your dispersion will increase to the new minimum based on the minimum sprinting state multiplier (which for the Assault Rifle is x5, or 3.75 degrees) at a speed of 3 degrees per second. Decaying from a dispersion value above your current maximum dispersion occurs at the normal dispersion decay rate. So thatGÇÖs dispersion. Keep in mind that dispersion is only one part of accuracy, along with kick and weapon range. Hopefully you now have a better understanding of how it works in DUST. CCP Logibro // Patron Saint of Logistics // Distributor of Nanites (a¦á_a¦á)


CCP Logibro C C P C C P Alliance 9397	Posted - 2014.10.07 19:45:00 - [2] - Quote matsumoto yuichi san wrote: ok in the table it gives dispersion numbers for the ASCR but the curve on the chart, and the data shows it being constant, along with the ARR, this seems wrong, mostly because it certainly seems to go up, but just my opinion :P As noted, the numbers you see are for stationary firing. Movement adds some multipliers that cause an increase to growth and min/max and a decrease to decay. CCP Logibro // Patron Saint of Logistics // Distributor of Nanites (a¦á_a¦á)


CCP Logibro C C P C C P Alliance 9397	Posted - 2014.10.07 19:47:00 - [3] - Quote Stefan Stahl wrote: Wonderful idea. I very much hope this becomes a series. That way we can start giving you much better feedback on the handling of the guns, which is one of the areas Dust doesn't do very well. CCP Logibro wrote: There are also some other numbers that affect dispersion we havenGÇÖt gone over yet. The first is the Zoomed Dispersion Multiplier. This increases or decreases the dispersion when looking down the sights of a weapon. Most rifles have this set to 0 Does anyone else agree that this shouldn't be the case? A bullet-hose shouldn't become a laser if aimed down sights. The AR is particularly at fault for this. I can see the reasoning: The sight should show you where the bullets go. I guess we just need horizontal recoil. Recoil/kick is a different part of the equation. If this continues that will be one of the other topics that I'll go over. CCP Logibro // Patron Saint of Logistics // Distributor of Nanites (a¦á_a¦á)


CCP Logibro C C P C C P Alliance 9412	Posted - 2014.10.07 22:42:00 - [4] - Quote Vell0cet wrote: Just to clarify, a bullet's trajectory is randomly determined with any value within the limits of the current dispersion? In other words, if I fire 30 rounds and have max dispersion, it's possible for all rounds to randomly be very close to center based on a random number generator, or are the shots guaranteed to vary by the maximum number of degrees from center? I'm pretty sure it places it somewhere in the cone (otherwise you could never fire a shot straight), but I can't remember what it uses to place it in the cone off the top of my head. I'll have to dig into it later. Fizzer XCIV wrote: Holy Christ. I love the fact that you guys are sharing this info, but that link was a nightmare. It opened at least 50 tabs on my browser (chrome), and just kept on opening them. I spent a good 5 minutes just trying to close them faster than it would open new ones... That sounds really strange, should be just a file download. Maybe your browser was freaking out due to it being a Macro Enabled Excel sheet, I'll zip it up and reupload it tomorrow when I'm in the office. CCP Logibro // Patron Saint of Logistics // Distributor of Nanites (a¦á_a¦á)


CCP Logibro C C P C C P Alliance 9428	Posted - 2014.10.08 10:45:00 - [5] - Quote J4yne C0bb wrote: First of all, thanks very much, I enjoyed the read. CCP Logibro wrote: Most rifles have this set to 0, meaning that they have no dispersion when looking down the weaponGÇÖs sights. The HMG has this set to 1, which means that it has the same dispersion when zoomed as when aiming from the hip. Lastly, we have the state multipliers. There are separate multipliers for the decay rate, growth per shot maximum and minimum depending which of four different states you are in: Crouched, moving, sprinting and zoomed. These allow you add things like bonuses for crouching or increase your dispersion after just finishing sprinting. To go along with these state multipliers we have GÇ£Growth Rate Below MinimumGÇ¥, which increases your dispersion by a certain amount per second when itGÇÖs below the minimum dispersion. An example of this would be if you start sprinting, your dispersion will increase to the new minimum based on the minimum sprinting state multiplier (which for the Assault Rifle is x5, or 3.75 degrees) at a speed of 3 degrees per second. Decaying from a dispersion value above your current maximum dispersion occurs at the normal dispersion decay rate. Very interesting. So if I'm interpreting correctly, zooming in on far-off targets with the HMG to try and decrease dispersion has absolutely no effect, other than whatever benefit is gained in order to track the enemy in your reticle? I ask because ADSing with the HMG has a slightly longer animation than with other weapons, and being in ADS has a detrimental effect on your peripheral vision -- I'm sure I've died more than once because of that. Also, since I'm always running as a fatboy, I should refrain running over to enemy heavies and start blasting -- whenever possible, I should let that dude come to me instead? No. While there is an overall modifier for dispersion while zoomed through the Zoomed Dispersion Multiplier, there is also a state multiplier for weapons while zoomed that allows more granular control. For the HMG for example, while zoomed you have a 0.9 and 0.8 multiplier to max and min dispersion, but no change to shot growth or decay. Additionally, I would like to again iterate that dispersion is not the same as recoil (otherwise referred to as kick). These are two different systems that work at the same time. Dispersion makes bullets land in a cone around where you're aiming, kick moves where you're actually aiming. CCP Logibro // Patron Saint of Logistics // Distributor of Nanites (a¦á_a¦á)


CCP Logibro C C P C C P Alliance 9428	Posted - 2014.10.08 11:54:00 - [6] - Quote DeathwindRising wrote: CCP Logibro wrote: No. While there is an overall modifier for dispersion while zoomed through the Zoomed Dispersion Multiplier, there is also a state multiplier for weapons while zoomed that allows more granular control. For the HMG for example, while zoomed you have a 0.9 and 0.8 multiplier to max and min dispersion, but no change to shot growth or decay. Additionally, I would like to again iterate that dispersion is not the same as recoil (otherwise referred to as kick). These are two different systems that work at the same time. Dispersion makes bullets land in a cone around where you're aiming, kick moves where you're actually aiming. is there a mechanic in place for reducing dispersion? what state offers the least dispersion and most dispersion? is there a method to reduce kick? if both dispersion and recoil play a role in over all accuracy, what would be the best way to improve overall accuracy? In general, being crouched while stationary will result in the best accuracy, while firing directly after sprinting while still moving will result in the worst accuracy. CCP Logibro // Patron Saint of Logistics // Distributor of Nanites (a¦á_a¦á)


CCP Logibro C C P C C P Alliance 9432	Posted - 2014.10.08 15:28:00 - [7] - Quote sabre prime wrote: The only thing I learnt from this article was: CCP loves numbers. Interesting to read how all the hidden mechanics work though. There are a lot of parameters that can be adjusted behiind the scenes. Also, why do you bother having a mechanic like 'dispersion decay'? Is it to model some kind of inertial force when firing a gun? If we didn't have dispersion decay, then there would be no way for dispersion to decrease. Effectively as you fired your gun, it would get more and more inaccurate the more you fired it without any means to recover accuracy. The reason we have a curve is so that we can choose to have dispersion decay (recover could be an accurate term to replace it) faster or slower if you're got higher dispersion. Just gives us more control of how the weapon handles. CCP Logibro // Patron Saint of Logistics // Distributor of Nanites (a¦á_a¦á)


CCP Logibro C C P C C P Alliance 9434	Posted - 2014.10.08 16:44:00 - [8] - Quote Echo 1991 wrote: Fox Gaden wrote: Echo 1991 wrote: loving the data and the graph, but it really shows that the gallente assault bonus should be changed. How can you come to that conclusion based on this data? The spreadsheet provides no information about Kick (recoil), which is much more of a factor with the Plasma Rifles. Kick is not lowered. Dispersion is. And the data shows that dispersion on the assault rifle isn't high so why have a bonus that lowers an already small value? Keep in mind the values you see are for firing while stationary. Movement adds state multipliers that increase dispersion. CCP Logibro // Patron Saint of Logistics // Distributor of Nanites (a¦á_a¦á)


CCP Logibro C C P C C P Alliance 9462	Posted - 2014.10.09 20:53:00 - [9] - Quote sabre prime wrote: CCP Logibro wrote: sabre prime wrote: The only thing I learnt from this article was: CCP loves numbers. Interesting to read how all the hidden mechanics work though. There are a lot of parameters that can be adjusted behiind the scenes. Also, why do you bother having a mechanic like 'dispersion decay'? Is it to model some kind of inertial force when firing a gun? If we didn't have dispersion decay, then there would be no way for dispersion to decrease. Effectively as you fired your gun, it would get more and more inaccurate the more you fired it without any means to recover accuracy. The reason we have a curve is so that we can choose to have dispersion decay (recover could be an accurate term to replace it) faster or slower if you're got higher dispersion. Just gives us more control of how the weapon handles. Thanks for the reply. Interesting to learn. So when we stop firing does dispersion automatically reset to the base value, or is the dispersion decay 'rate' still in effect? I would expect a gun to get more inaccurate the more it's fired. To recover accuracy, just stop firing and then start again? Dispersion decay is always affecting the dispersion value, whether you're firing or not. This means that when you stop firing you recover dispersion quicker; however this is not caused by the decay rate increasing, but by the lack of any growth from the gun firing. So yes, if you want to recover dispersion, you stop firing and wait for it to recover. The dispersion doesn't instantly recover, but it usually takes less than a second for most rifles. As pointed out in the OP, another artefact of always having dispersion decay active is that a weapon can actually have a soft cap on it's dispersion below it's hard cap. You'll notice that none of the rifles or the SMG ever come close to their maximum dispersion. This is due to them reaching an equilibrium point where the rate of dispersion decay gets high enough to equal the rate of growth. CCP Logibro // Patron Saint of Logistics // Distributor of Nanites (a¦á_a¦á)


CCP Logibro C C P C C P Alliance 9472	Posted - 2014.10.12 23:34:00 - [10] - Quote Jathniel wrote: Any particular reason why it's in .xlsm format? No quick online viewers for that... Whatever. Regular .xls that bad? It uses a macro I wrote to calculate the dispersion. I was going to post a version with just the numbers but I thought you guys would want a chance to play around with some numbers (especially since dispersion values have now been added to the SDE). CCP Logibro // Patron Saint of Logistics // Distributor of Nanites (a¦á_a¦á)