[PHYSICS] Ball bounce physics (especially on the green)

[Blackadar]

Does anyone else think that the physics regarding the way the ball bounces - especially around the green - needs some work?

I've noticed that even on stimp 8 and 9 (moderate firmness) the ball tends to bounce far too much with the slope when hitting the green. If it hits any slope, the kinetic energy of the ball seems to transfer totally from going forwards to severely bouncing to the slope side. And because the green slopes that way, the bounce becomes a prolonged roll to one side or another. This oftenr results in ball bounces and rolls of 30 or 40 feet perpendicular to the original flight of the ball.

I'm not talking about huge undulations either. I'm talking seemingly slight slopes that bounce the ball 15-25 feet from it's intended direction. This doesn't really happen in real golf. The backspin on short irons and the forward momentum on longer shots tend to negate bounces like this. The intertia of a golf ball due to these factors actually make it difficult to change the direction of the ball all that much when landing. Once it starts rolling on the green then it's more subject to the curves of the green. But not when landing or bouncing.

The harder the green, the more the slope impacts the ball. So I would understand it if I were hitting into greens baked to the consistency of concrete. But not on moderate firmness. Even on very high pitch shots - 64 degree wedge jacked all the way up, which means the ball should stop when hitting a green - tend to get sucked one side or another for lengthy rolls. When I stick a five iron right at the flag and it caroms off a 1 foot mound to wind up 40 feet to the left or right, something isn't tuned quite right

Or is it just me?

[USAFDad]

I'm finding what I consider excessive roll on the green. Rarely am I short on an approach shot, almost always long.

[ahhyeaa]

I play with the stimp at 12 so it feels great to me, but i see what you're saying. If the greens are soft it should hold more. Have you tried changing the firmness? The default is 7. I haven't messed with it, but maybe lowering it might help. I think firmness is a global setting though for the whole course, not just the greens. I've noticed that rain doesn't seem to soften the greens either.

[Blackadar]

Originally posted by ahhyeaa:

I play with the stimp at 12 so it feels great to me, but i see what you're saying. If the greens are soft it should hold more. Have you tried changing the firmness? The default is 7. I haven't messed with it, but maybe lowering it might help. I think firmness is a global setting though for the whole course, not just the greens. I've noticed that rain doesn't seem to soften the greens either.

I have reduced the green speed and it doesn't seem to make a difference. The ball doesn't roll quite as far, but the caroms are still considerably more severe than I've seen in real life (and I used to play in the mountains so I'm used to some severe slopes). Of course, maybe it's just me.

[ahhyeaa]

There are 2 settings. One is the stimp meter that adjusts the speed of the greens. The other is the firmness. It determines how hard or soft the course is, i think. If you adjust this it may effect the whole course and not just the greens.

[Tiberius]

ahhyeaa is correct, stimp does not affect bounce in any way it just alters the green speed and firmness affects ground hardness and bounce coursewide but not rolling speed.

[Blackadar]

Here are a few videos that may help explain what seems off to me.

Note that the settings were for firmness of 1 and stimp of 9 - the very lowest settings allowable in the game. Let me stress this - these greens are as slow as they can get. Anything higher will magnify the issue. So if it just looks like a minor thing, it's not when the green speeds are fast or the slopes even more pronounced.

The videos are compressed. The game looks far better on my computer. So if anyone says that the graphics look bad, that compression and not the game. I greatly reduced the resolution to make it faster to upload. I have the originals if they're needed, but I think the point gets across even in lo-res.

All of these were from the same round.

Also, all of these shots were taken with a wedge (52 degree). This type of shot therefore shouldn't roll. On very soft greens, it should check up and stay put. I'm trying to take as much variability out of these examples as well.

Finally, the three shots in these videos actually all worked in my favor. I didn't want anyone to think I was complaining about a bad bounce.

http://youtu.be/GzSvX1sY0E4
Wedge from the tee into a soft green. Note it hits the slope on the left side and takes almost a sidewards bounce. But it's really the 2nd and 3rd bounces that look off to me. It's like it was gathering steam downhill when in reality it shouldn't have with that club and those conditions. Then it proceeds to roll almost 20 feet sidewards. That's from a pretty inconsequential slope.


http://youtu.be/9TkTp-0Zk_w
I think this one shows it best. The ball is tailing off (I faded it) and it hits the moderate slope on the left side. Again, that ball should have either stayed there or bounced forward. Instead, it hops 90 degrees to the right and rolls over 20 feet. It's a more severe slope, but the effect here is greatly pronounced.


http://youtu.be/aJpQWDfxSP8
What's wrong with this one you may ask? Watch the flight of the ball. I sliced the ball and the wind was pushing the ball the same direction. Look at the flight of the ball - there's no way that ball hops almost straight up on such a mild slope and then proceeds to work from left to right. From a real world physics standpoint, there's no way that ball can hop any direction but left - it's tailing off far too fast.


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http://youtu.be/tvFRGz8V2RI
This one is in high res for obvious reasons and isn't related to the bounce issue. Occasionally I'll see slightly weird interactions with the hole edges. This one happened in the same round so I thought I'd post it. Note how the ball speed is slowing down at the cup and kind of "bumps" the lip twice. Each bump seems to make the ball speed up and it really kind of flies out. Then it hits a small slope and seems to gather even more momentum. It's close, but it just doesn't look quite right to me. I lipped the putt no doubt, but it was dying at the hole - maybe going 12 to 18 inches past - and the odd lip mechanics threw it almost 5 feet out.

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Note that I am not trying to be nitpicky, just pointing out things as I go so PG can be the best golf sim it can be (it's already the best on the market IMO). And none of these are glaring issues, but they're just slightly off IMO.

Still lovin' the game! 60 FPS on my slightly outdated machine and looks great to boot. The gameplay is relaxing and fun. Can't wait to see what's next!

[Tiberius]

Thx for the input, I don't think there's too much wrong with the first two as the ball hits onto a severe sideslope on the first and a sidelope/upslope on the second and it react pretty much as I would expect. The third one is hard to see but the ball bounces pretty straight and then spins off the sloping part of the green towards the pin - If I saw anything wrong with that I would say so but I really don't.

The putt I agree looks off, our lip physics need some work for sure.

[Ch3apTrick]

What I seem to have noticed is if you firm up the greens the whole of the fairways seem to have same firmness and the ball bounces like a tennis ball all over the place.
Played a round with firmness 10 and Stimp 9
Try it yourselves ball reacts like a tennis ball,surely it should be just the greens that have the firmness applied to it?

[USAFDad]

Originally posted by Ch3apTrick:

What I seem to have noticed is if you firm up the greens the whole of the fairways seem to have same firmness and the ball bounces like a tennis ball all over the place.
Played a round with firmness 10 and Stimp 9
Try it yourselves ball reacts like a tennis ball,surely it should be just the greens that have the firmness applied to it?

You are correct in that 'firmness' affects both the fairway and the greens. Based on posts that I've seen, that is a change being considered. I would expect to see a change in this area in the near future sometime after the conversion of the game and all the courses from Unity 4 to Unity 5 which is in process.

[Ch3apTrick]

that will help the ping pong effect for sure as you cannot have serious ball physics when turning firmness to 10