HorDispersion and VerDispersion

#1

When using the BF1 Weapon Comparison tool, I notice that shotguns have nonzero “HorDispersion” and “VerDispersion” values.

I am not sure what these refer to, and how it’s different from spread (if at all). In particular, I want to know how it interacts with the minspread present when hip firing (do I add Hor/VerDispersion to the 0.4 degrees of stationary hipfire minspread)?

Note: I am already aware that BF1 shotguns’ spread are evenly distributed over the radius of the spread circle (as opposed to the area).

Edit: The crossed-out statement is wrong. See below.

#2

Those values control the shotgun’s pellet spread. It’s how a wide distribution such as from the Duckbill in BF4 is done.

The normal dispersion values inside the gunsway file still apply (I think) but have comparatively less influence.

#3

I see that the M97 Sweeper is the only shotgun with any difference between VerDispersion/HorDispersion. For all other shotguns, both dispersion variables are the same.

So consider we’re talking about any shotgun that isn’t the M97 Sweeper; let’s pick the Model 10-A Factory. It’s VerDispersion and HorDispersion are both 2.25. If I ADS while standing still, does the spread cone have a half-angle (the angle alpha in this image) of 2.25 degrees?

The Model 10-A Factory’s moving hipfire minspread is 0.6. So If I hip fire, is the spread cone’s half-angle now 0.6 + 2.25 degrees?

#4

All correct.

Though I do have to correct you on pellet distribution over radius and area. The pellets are forcefully distributed into separate zones within the cone so it’s not over the radius. It’s closer to over the area.

#5

I did not know that! Thank you. However, this begs more questions:

  • Are the “two separate zones” the inner and outer halves of the circle?
  • Are half of the pellets in each of the two zones?
  • Are individual pellets evenly distributed by radius (and uniformly distributed by angle) within each zone?

And now I have to wonder how spread/dispersion works for the M97 Sweeper. It seems natural that the spread cone would now an elliptic cone, meaning that the cross section at wherever my opponent is located is now an ellipse instead of circle. Quantitatively, if my opponent were L meters away, then the major axis of my “spread ellipse” would be L * tan(spread + horDispersion), and the minor axis would L * tan(spread + verDispersion).

#6

Inside the game data there are settings for NumSubdividesForUniformDispersion and NumInnerCirclesForUniformDispersion. When enabled, these together create a spider web of areas each pellet can go into. For the 97, this is set to 3 subdivides and 1 inner circle. This leads to 12 areas in total and looks something like this.

The total area count matches the number of pellets so that one pellet goes into each section.

This screenshot is from BFV’s weapon designer and shows 32 areas in total for the 32 pellets of its M97.

dca003926ca7ec9eb8209e692f7146a8.png1200×675

#7

Thanks so much, Noctyrne.

Would you happen to know how the game distributes the pellets within each region? And are you able to confirm or deny whether a difference between verDisperion and HorDispersion lead to elliptical cross sections?

#8

I would assume the divisions would account for ellipses but since none of the shotguns use that, we can’t really verify.

As for the distribution, I have no idea. My guess is that it will attempt uniform dispersion over the area of the section.