is it possible to have floor contacts for parts other than feet or hands?

#1

Hello all!

Is there a way to establish a floor contact for parts other than feet and hands? Let me explain what I need. I have a character with a tail that has been characterized in MB. The tail was added to a bvh file using skeleton nodes and parented to the hips. I’ve managed to animate the tail by using a series of relations constraints to give it a natural looking animation when the character moves around. My problem is that in several parts of the animation, the tail goes below the floor.

Aside from manually keyframing the tail in those areas, is there a constraint or something else I can use to have the tail recognize where the floor is so that it doesn’t go through it?

Thanks in advance for the help…

Bryan

#2

the first thing that comes to mind is to use a constraint…

#3

OverEZ:

Yep, I know, but what constraint? I just need a little direction on what to use…I haven’t had any luck finding anything that talks about this… any suggestions?

keep them suggestions coming!

Thanks!

Bryan

#4

hey sorry man super busy right now…the expression constraint may be your best bet…there’s some documentation in HELP, where you might be able to constrain something to not go under 0 on the Y-axis…

#5

It depends on the actual result you need to accomplish and how precise you need it to be. Do you need it for real-time display (I mean a live show or something) ? The purpose is always relevant, because it can (and most of the time will) set limitations.

Anyway, you can use an expression constrain if you have the tail setup with an IK effector at the end. But most likely the result would be the tip of the tail barely touching the ground and not going under it. But if need to get detailed floor contact, something like the “Sticky” and “Spread” functions of the hands and feet floor contact setup you would have to spend a lot of time R&D-ing a constraints setup to be able to pull it off. Again depends on the level of detail you need.
Cheers, let us know how it turns out, maybe we can all solve this together :wink:

#6

OverEZ and Dawnweaver:

First of all, thanks for the responses… the easiest thing would probably be to show you a clip of what I’m doing…

You can find that here: http://www.kkstudio.us/Output.html

I’m not doing anything live, what I intend to do is to export this back out to bvh to apply to an existing character of a mouse. I added the bones to the bvh by adding additional skeleton nodes which were parented to the hip. (but I don’t think I have an IK effector for the end of the tail…not too sure how I would go about doing that)

As you can see…although not too bad, parts of the tail go underneath the plane that I’ve setup as the floor for the character. I would like to have the tail drape down naturally on the floor and have it skid across it as the character moves around. Could I create a constraint so that the skeleton nodes are attracted to the plane (for the drape), not go below it and still have it move around naturally? I’m not versed at all with constraints, as I’m relatively new to this, so please bear with me…I would’nt have the slightest idea on how to word it…

thanks again for your help…

Bryan

#7

There is this: http://www.brekel.com/?page_id=58

A plug-in by Jasper Brekelmans. But you need to be able to use the AgeiaPhysX engine. I heard there will be (or maybe already is) a release of the NVIDIA drivers that will enable the owners of 8*** series videocards to take advantage of this. Right now from what I see you need to “fake” gravity (because now you have none), collision (with the floor and possibly with the rest of the body) and you have to take down the damping on the tail a little. It could be just me, but it looks really floaty the way it is now.

Let us know if you have any progress, I think many would welcome a solution to this issue of yours, because tails are a common character extension nowadays :slight_smile:

#8

Dawnweaver:

Thanks for that info! I’ve already contacted Jasper to see if I can get a copy of the plugin… meanwhile… How would I fake collisons and gravity? The damping I can correct, it is just a matter of changing the value of the damping in my constraints.

I’ve searched for gravity and collisions in MB and cannot find much, although I do see a setting for gravity in one of the relations constraints options… but have no idea on how I could use it… suggestions? just a kick in the right direction would help…

meanwhile I’ll play a little to see what I can get…

thanks again for the suggestion…

Bryan

#9

I first of all want to thank Jasper Brekelmans for the solution he gave me for this issue… I got his plugin but unfortunately was not able to get it to work on my laptop at the time… but he suggested something else that did work.

To simulate collisions on the floor… he suggested using a relation constraint that clamped the y translation values of the skeleton nodes for the tail.

in the constraint, you would connect the translation node of tail01 to the x vector of a “scale and offset vector” box… add values of x=-9999999, y=0 and z=-9999999 in the “clamp min” variable and then connect the resulting value back into the translation node of tail01… so on and so forth with all the tail nodes. (similar to what you do with 3d damping) The solution worked great! The nodes as they hit that floor, would not go below it. You can adjust that y=0 value to adjust for the thickness of the tail of your character.

Now if I could just figure out why the resulting bvh is not mapping correctly in my target application, I will be sitting pretty. (I need to test in other apps to see if it is something being output by mb, or something in my target app… which in this case is Poser… I will try 3dsmax to see what results I get)

keep you posted…

Bryan

#10

hmmm… it seems it might be something I’m doing wrong in MB… when exporting the whole skeleton out as fbx to import into 3ds max… I am getting some movement, but not what I’m getting in MB… In 3ds max the tail is stiff, moves very little and kinks in places…not the fluidity that I get in MB… exact same thing I’m getting as a bvh…

Ideas? I’m plotting to control rig and back to skeleton, then exporting… Ideas?

thanks!

Bryan

#11

duh! I hate when this happens… looks like I forgot to “plot all” under animation…

Bryan

#12

Sorry for not keeping up with the pace of the issue :slight_smile: Glad you an Jasper figured things out. It’s really cool that you kept us up-to-date on this. The clamping trick seems like one you could use over and over again even for different stuff. Cheers :wink:

#13

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