On Monday and Tuesday, Havok 4 was implemented across the SL main grid. H4 is a major upgrade to the physics engine that’s critical for many things in Second Life, including sailboats.
This morning Vin Mariani and I did a few “first look” tests to check out how boats handle collisions on the main grid under H4.
I’m sure you know the problem. You’re in the middle of a race and someone tacks in front of you. You try to veer away but your boat catches in their rigging. More likely than not, both boats end in a tangled mass of fiberglass and Mylar as the crowd looks away in horror. If you’re lucky enough not to crash off-world, you frequently need to stop, take a deep breath, and rez a new boat.
Well, sports fans, it looks like those days of sailing carnage may be a thing of the past with H4! This morning Vin and I repeatedly collided a Larinda Lite and a Full Tradewind into each other. We never “fused” or crashed. The usual result was a moderate “bounce.”
If you look at the sequence of images to the right, you’ll see an example. In A-B, both boats are asail, and Vin’s Larinda Lite collides with my Tradewind. As you can see in C-D, Vin’s boat just bounces off. In this case, Vin was thrown well over 100m, which seems pretty extreme. However, in all other attempts today, the bounce was much smaller and seemed fairly reasonable.
It’s worth noting that in all our collision attempts the Larinda bounced while the Tradewind was minimally affected; every time the Tradewind hit the Larinda head-on, the Larinda was pushed back. This may be due to a ‘mass effect,’ since the full-sized Tradewind is far more prim-heavy than the Larinda Lite.
The pictures below show another example of the collision effect under H4. In ‘A,’ Vin’s Larinda hits the Tradewind’s port bow at an angle. ‘B‘ shows that the two boats very briefly overlap, and then the Larinda ‘bounces back’ a small amount (‘C’). The extra space gives both boats enough room to slide past each other safely (‘D’).
A similar bounce takes place when boats hit the End Of the World (EOW). The magnitude of that bounce appears equivalent to what occurred in H1. However, as they always say in science journals, “more research is indicated.“
25 responses so far ↓
1 Aislin Keynes // Apr 2, 2008 at 10:33 am
It’s so nice to hear that this problem may be fixed. You didn’t mention and I couldn’t tell from the pictures, were these tests run at sim crossings? That is normally where I see fused boats but it’s really hard to duplicate.
2 Jane Fossett // Apr 2, 2008 at 12:41 pm
I completely agree with Aislin. Sim crossing is a big issue, and I had no problem with it during the testing we did this morning. Of course, that doesn’t mean anything at all. We will all need to monitor it over the next few days….
3 Owen Oyen // Apr 2, 2008 at 1:27 pm
Preliminary measurements show no surprises.
Boats HAVE been raised from the last beta deploy, so Andrew Linden did get that done.
Wave motion is broken. I did all I could with Simon Linden on it. I am told it’s not just the ACC. The other boats that have adopted wave motion are broken too. This is sort of good. It gives me some more ammo when I present it to Simon and Sidewinder — probably tonight.
4 Jane Fossett // Apr 2, 2008 at 2:04 pm
Considering the extensive work Owen has done preparing sailboats for H4, last month I emailed Pope Benedict XVI nominating him for sainthood.
I got a polite note back from the College of Cardinals saying my request was inappropriate.
Nonetheless, they said the Pope was fully aware of Owen’s contribution to the global SL Sailing Community and Benedict wanted to know if Owen had any unpaid Vatican parking tickets.
Owen?
I think they’re willing to talk…
5 Owen Oyen // Apr 2, 2008 at 2:59 pm
Well, this gig has been unpaid in total. So I would prefer to accumulate Vatican brownie points on this for later use.
Though . . . it would be nice if that could upgrade those clown uniforms the guards wear. I was there about 6 years ago and in my ignorance I did presume they were there to entertain the children
http://www.inforoma.it/feature.php?lookup=swiss
6 jane fossett // Apr 2, 2008 at 3:24 pm
omg…
somehow I always believed the Vatican Guard wore those clown suits because the uniforms were reverently designed by Michelangelo.
Now it turns out… Mirabile dictu… they were a wholesale purchase from the Britney Spears collection at Wal-Mart…
(ask Clement VII)
7 jacqueline trudeau // Apr 2, 2008 at 4:14 pm
“a tangled mass of fiberglass and Mylar “
8 jacqueline trudeau // Apr 2, 2008 at 4:14 pm
*cough*
9 jane fossett // Apr 2, 2008 at 4:37 pm
Jacqueline Trudeau commented: “a tangled mass of fiberglass and Mylar “
JFos says: Actually…
I think in the above picture Pope Clement VII was wearing a “retro” polyester cape with matching cap offset by a tasteful flexi-skirt.
10 Hpathe Boucher // Apr 3, 2008 at 6:29 am
The official dress uniform is of blue, red, orange and yellow with a distinctly Renaissance appearance. A repeated historical misconception is that the contemporary dress uniform was designed by Michelangelo. In fact, Commandant Jules Repond (1910-1921) created the current uniforms in 1914. While the uniforms of the Swiss Guard bearing Pope Julius II on a litter (painted by Raphael) is often cited as inspiration for the Swiss Guard uniform, the actual uniforms worn by those soldiers are of the style which appears by today’s standards as a large skirt, a common style in uniforms during the Renaissance. A very clear expression of the modern Swiss Guard uniform can be seen in a 1577 fresco by Jacob Coppi of the Empress Eudoxia conversing with Pope Sixtus III. It is clearly the precursor of today’s recognizable three-colored uniform with boot covers, white gloves, a high or ruff collar, and either a black beret or a black morion (silver for high occasions). Sergeants wear a black top with crimson leggings, while other officers wear an all-crimson uniform. The regular duty uniform is more functional, consisting of a simpler solid blue version of the more colorful tri-color grand gala uniform, worn with a simple brown belt, a flat white collar and a black beret. For new recruits and rifle practice, a simple light blue overall with a brown belt may be worn. During cold or inclement weather, a dark blue cape is worn over the regular uniform. The original colors (blue and yellow) were issued by Pope Julius II taking his family (Della Rovere) colors, Pope Leo X added the red to reflect his family’s Medici colors.
11 Hpathe Boucher // Apr 3, 2008 at 6:31 am
Nonsense, everybody knows the uniforms are made in Spain, and reflect the colors of the House of Borbon. Who is Michelangelo? pfft.!
12 Jeancarlo Kepler // Apr 3, 2008 at 7:55 am
“Wave motion is broken. I did all I could with Simon Linden on it. I am told it’s not just the ACC. The other boats that have adopted wave motion are broken too.” Owen Oyen
Well not in every boat .. ive been sailing the Tetra 35 since the H4 came up and .. still works in this one .. and looks lovely as usual (=
13 M1sha Dallin // Apr 3, 2008 at 10:01 am
I thought it was more ‘jerky’ than normal whilst doing my knotlap in the Tetra. Though this may have been the grid itself.
14 Jacquline Trudeau // Apr 3, 2008 at 10:38 am
Sorry my comment touched off a minor skirmish regarding Papal attire. I really was referring to Jane’s description of the composition of the Tradewind. I believe those materials hadn’t made their way into the hands of 18th and 19th century shipwrights.
15 jane fossett // Apr 3, 2008 at 5:03 pm
Grin!
Meanwhilst, back at Tradewind collisions under H4…
Today JeanCarlo Kepler repeatedly collided his 255 prim Tetra into my Tradewind Lite (155 prim). The Tetra has far more prim, but is physically much smaller than the TW.
In each case, when the boats collided the Tetra bounced away while the TW barely budged. I assume this this has to do with how H4 calculates the ‘mass’ of the attachments based on volume, not prim number, but obviously there are many other factors involved.
Thank you to Yuu and Bato for helpful discussions on this!
16 Chaos Mandelbrot // Apr 3, 2008 at 6:40 pm
I hope Jacquline has plenty of hardwood prims available to fix all the damage your tradewind has suffered
17 Caf Binder // Apr 3, 2008 at 9:38 pm
Last sunday, March/30, what is recorded on Sail On, I was bumbed all the way to the beach (Tako bumped by a Fizz). I was bumped from Trudeau Cay to Santa Catalina, it seems. Not really probably… maybe just some (BIG) sim cross glitch.
Anyway, were those sims already on H4 by that time?
18 Owen Oyen // Apr 4, 2008 at 12:25 am
As best I know, which may not be comprehensive, even the early adopter regions of the Main Grid did not get final version of H4 until the Monday-Tuesday sequence.
Sidewinder is on my friends list and he has been absent for a few days from login, which is to be expected because he was on a ton of hours the last few weekends — so I have no replies back from him yet, and they are not overdue.
I don’t have much to say about collisions. RL collisions come in flavors . . . elastic and inelastic and how physics work for those varies by degree and angle and all sorts of stuff that . . . if Havok 4 attempts to emulate for every prim in a CPU one would think it cannot happen in a reasonable time period. I don’t know anything about what was done for avatar mass or what collision response will be as a function of mass in H4.
Some collision issues were mentioned as being known problems and work still proceeding on them.
I will say that I have heard some reports of “stuttering” with regards not only wave motion, but also forward motion. I observed the symptom this past evening. BUT. On a later login I did not see it. The basic wave motion being broken is always there, but the forward motion stuttering is not present all the time on each login.
Meaning . . . I think something other than purely Havok 4 has a problem. Maybe a side effect. Maybe an incompatibility. But if some pure physics algorithm in H4 were wrong in such a way to produce this uneven forward motion, it would always be wrong. It’s not. I have seen it work okay earlier this evening.
19 jacqueline trudeau // Apr 4, 2008 at 5:37 am
Caf, I was anxiously checking the help about - the Trudeau sims were not updated until sometime late Tuesday, the 1st or early Wednesday, the 2nd.
20 Liv Leigh // Apr 4, 2008 at 8:36 am
My experience with Havok4 so far has been ok. Not mentioning the recent quality of the grid. Havok4 servers seemed to act nicely.
One remark here: “This may be due to a ‘mass effect,’ since the full-sized Tradewind is far more prim-heavy than the Larinda Lite.”
If I recall… the prims are in wearables.. Will this mean that wearing my prettiest prim-heavy boots will make my boat survive collissions much better now in the heat of a race?
21 Elisha Paklena // Apr 4, 2008 at 8:41 am
Good test would be to try the sailing in just the vehicle parts, sans the wearables…
22 jane fossett // Apr 4, 2008 at 5:15 pm
Elisha said: “Good test would be to try the sailing in just the vehicle parts, sans the wearables…”
Elisha? Sigh…
With so much going on recently, I had really hoped everyone forgot about MarkTwain’s idea to hold a “Nude Wee Tiny Tako Regatta.”
If what I wear sailing slows me down in H4… grin… so be it.
I’m not testing boats “sans wearables.”
23 MarkTwain White // Apr 4, 2008 at 7:30 pm
I believe the Nude Wee Tiny Tako Regatta was Nber’s “brain”child. GRIN. I really do think she and Aislin plan to do it.
24 Elisha Paklena // Apr 5, 2008 at 10:47 am
Tiny Tako? Feh. 40% of the time I sail in what Bast gave me, once I get out of Mowry…
Why not? It’s fur! I’M NEVER NAKED.
25 Jane Fossett // Apr 21, 2008 at 12:02 pm
OK OK, I knew it would happen…
Despite H4, I had an old-style boat-mangling crash this morning at the start of Monday Morning Big Boat Races.
There was a sizable race fleet, but I doubt that was the major contributing factor. Immediately at the start I was jockeying for position, scraping hulls with the windward boat as we crossed the West side of the passages line.
Soon after, my windward opponent’s boat broke apart. The hull sank like a rock, while the vehicle, including sails, stayed afloat.
My boat spun around, deeply entangled in the wreckage of the fatally damaged Tradewind adjacent to me. I was unable to break free and I quickly decided to rez a new boat.
Oh, well… so much for H4…
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