Walking Ragdoll?

Troubleshooting physics
1

I am pretty new to programming games and am considering making some mech warrior tests.  I would like to have all of the robots as walking ragdolls so that they react to impact realistically, but cannot think of a non-hacky  way of doing things.  Since really only the feet need to move, and it doesn't need to look natural I am considering having the body "float" with an upward force, and the feet be heavy enough to hold it down, they just have the legs move in a predetermined way, but I am not really sure how this is normally done, and couldn't find much written on it.  I would prefer to avoid complexity.

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691175002 said:

I would prefer to avoid complexity.

hmm, then don't use a ragdoll :wink:

Controlling a ragdoll to behave physically is complicated - what about using an animated Mech (where animation comes from your modeler) and only detecting collisions for limbs, body etc. individually?
3

You can set the Limit of the axis of the physical Joints. when you call setPostionMinimum and Maximum with the same value. the Joint is fix.

I worked a short time with this Ragdoll, if you set all Degrees to Zero, the doll stand in the PhysicalRoom and doesnt move. But I tried to get ich walk like a Human, so Joints needed more Axis then one, and in ODE you cant control these Joints.



But for a RobotWalk it could be makeable, if you use BezierCurves for Interpolation, it can look quite smooth.

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.:emp...hellg:. said:

so Joints needed more Axis then one, and in ODE you cant control these Joints.

you can, but it's really complex to get nice robot-like (or even human-like) movement
5

ohh yes!! or with inverse Kinematics  :slight_smile:



but me would interest, how to put the ready animation to ODE? You dont work with Joints then?

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I am trying to think of a stable way of making the mech walk believably and respond to impacts and crashing into things without adding excessive complexity.  I think I will create an invisible box or something and fix the ragdoll to it so that I can control the position of the ragdoll by applying forces to the box.  I will just make the legs follow a predefined path by setting fixed joints so that it looks like its walking, and walking into things or getting hit will make it flop around a bit without falling over.



Is there any way to prevent an object from moving rotationally?



I can't figure out how Joint.setSpring(); works.  I have tried a bunch of different numbers but the joint always acts the same for a rotational joint.  Does it only work for translational joints?

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.:emp...hellg:. said:

but me would interest, how to put the ready animation to ODE?

You could simply make the mech a static node (so ODE does not control it), import the animations from file (e.g. Collada) and trigger different "hit" animations upon collisions. (So, yes, without joints)

691175002 said:

I can't figure out how Joint.setSpring(); works.  I have tried a bunch of different numbers but the joint always acts the same for a rotational joint.  Does it only work for translational joints?

Not sure which joints work (see ODE docs for erp/cfm, please), at least fixed and ball joint (no/all rotational axes) do work with springs. But I think for your mech you cannot really use springs for the rotational joints (would look very weired - like a rubber mech :P)
8

Ok, sounds good, I'll try it, in this way,



thanks irrisor