Trigonometric walk cycle

[ELCGames]

So, I've recently been trying to step up a little with my platforming games and stray away from one-segmented bosses. I'm trying to create a massive boss that has separate segments for legs, arms, head, body, hands and fingers, so I figured I'd start by tackling the most basic element of its movement: The walk cycle.

I have two segments for each of the legs, and connecting them to the body shouldn't be too complicated, but my problem lies in how to move the damn things in a way that looks natural. I have a pretty good grasp on trigonometry and vector movement, but implementing any sort of knowledge into the game baffles me.

Has anyone ever done this sort of thing before? If so, some help and/or an example of going about this would be fantastic.

[Eliyahu]

The problem you're going to have is that what you want is NOT a simple trigonometric function. What I suggest is to plot your own graph of what you want the x and y positions of the loop to be for each limb, then a graphing calculator such as a TI-83 or TI-84 can take a list of points and make a guesstimate linear, quadratic, quartic, logistic, trigonometric, or power equation for you to use that looks like your plot of points.

[RickyRombo]

http://www.clickteam.com/website/usa/img/uploads/tutorials/download/body_parts_tutorial.pdf

[ELCGames]

The problem you're going to have is that what you want is NOT a simple trigonometric function. What I suggest is to plot your own graph of what you want the x and y positions of the loop to be for each limb, then a graphing calculator such as a TI-83 or TI-84 can take a list of points and make a guesstimate linear, quadratic, quartic, logistic, trigonometric, or power equation for you to use that looks like your plot of points.

Not sure I entirely understand. The point about plotting the points on graph paper sounds easy enough, but with using the graphic calculator, how would I go about plugging the information in? Should I just plug in all of the points, or find out the equation for each of the individual "frames"?

[RickyRombo]

I think he means plot out where you want the body parts to move, and try to use an equation to connect them.

[arfa]

Have a look at:
http://www.idleworm.com/how/anm/02w/walk1.shtml

Walk cycles are not easy but are incredibly effective in defining your character. You can get away with as few as 3 (rough) or 5 - depending on how good your artwork is. I find working with vectors to be the easisest.

[MuddyMole]

A really easy way to connect all the segments, is to use a combination of action points and hotspots.

For example:
The body object has its action point at the hip.
The upper_leg object has its hotspot at the hip, and its action point at the knee.
The lower_leg object has its hotspot at the knee.

Then you just say always:
Position upper_leg at 0,0 from action point of body.
Set angle of upper_leg to angle of body + ...
Position lower_leg at 0,0 from action point of upper_leg.
Set angle of lower_leg to angle of upper_leg + ...

To actually animate the model, you just need to change the relative angles.

You article that arfa linked to is a good start.
You can use those 8 frames as keyframes, but that won't be nearly enough for smooth animation of a large boss - you need to interpolate the positions/angles of segments between those frames (so you update them every frame - ie. 50 times per second).

[ELCGames]

Have a look at:
Walk cycles are not easy but are incredibly effective in defining your character.

Yeah, I should think that once I have one trigonometric walk cycle loop down, I should only have to jump in and edit some alterable values to change the type of character it's used for. i.e. Slowing down the speed and changing the length of strides to create a slow, lumbering giant.