I assume that all designers know that Jack's maximum speed, when running left or right is 4.

Now, when Jack jumps up he has only one speed, no matter if he is jumping left, right etc. But what is his speed? Well, it is between 8 and 9. Is that important?

It may be. When Jack stands on a platform going up:
- and that platform has a speed between 1 and 8, Jack is able to jump on that platform;
- and that platform has a speed between 9 and 20, Jack falls through the platform down when he jumps, because the platform is going faster up than he does.

yeah thx  :)

And there is a limit speed such that jumping on a platform which moves  downwards will result in the loss of a Jack. Er, do you happen to know this speed as well?

Yep: 5. At 6 he dies.

How did you calculate those numbers, Freddy ?

I would guess he just measured them, letting Jack race against a skeleton for example. (Or jump on a moving platform for vertical speed - this, for some reason, had got me puzzled for a while).

Although... Is the "5" speed of a skeleton the same as the "5" of a skull spider or a moving platform? If I remember well, the speed of a red bird is twice the speed of the blue one.

(Eh, who said I'm obsessed by birds?  >:( )

Horizontally I was refering to scorpions or skullspiders and vertically to moving platforms.

Er...don't we already know all this? No offense or anything, but did you see the post from Vern in "Modeling Jack's World"?

Quote:

Here are some values, given in pixels per frame, for Jack: Walking speed - 2.5 ppf Climbing speed - 2.2 ppf Pole sliding speed - 6.0 ppf Maximum falling speed - 12 ppf Gravity - 1.3 ppf (i.e. most objects accelerate by this amount per frame) That's all I got. Jumping is tricky, so I can't really explain it. It's different from falling though. The mechanics are totally different. He normally falls much faster than he does during a jump.

I assume, Freddy, that those numbers you posted are numbers you type into a box in the editor. The problem is, those numbers create different speeds depending on WHICH box you type them in. I figured out the conversions for most critters and platforms, also posted to "Modeling Jack's World".

Honestly, guys, this stuff's been out there for months. :D ;D

I was aware of those ppf's. But, I thought that, besides this technical info which is obviously more correct, a lot of players and designers could have some interest in the probably more useful speeds from the editor-boxes.

Freddy wrote on 06.01.2008 at 13:12:06:

I was aware of those ppf's. But, I thought that, besides this technical info which is obviously more correct, a lot of players and designers could have some interest in the probably more useful speeds from the editor-boxes.

Check. But...which boxes? Again, the numbers produce different speeds depending on which creature/platform they're applied to. Saying "Jack's speed is 4" doesn't mean much, because if you tell a bird to go "4" and a Medusa to go "4", the medusa will go much slower.

Granted, most critters share the same "speed numbers" as the platforms, so that's a sensible base. You can get a lot done with that, as long as you realize that some things won't work until you learn how to interconvert the speed numbers. I personally find it easiest to work in PPF (or TPF), but if that's hard to understand you could get by with a few multipliers to interconvert the different speed numbers.

Just a side-note: MM2 avoids the "falling through platform" by making Jack's jumping speed be affected (somewhat) by the platform he is riding.

I think platforms can go up to 14, or maybe 20, safely, with Jack on them. I forget which at the moment. But I think Mt. Peril's platforms demonstrate a maximum speed for the platforms that is still safe.

MM1 hasn't been changed in this regard, so its vertical platforms must stay slower to be safe.