IK Chain naturally move hips

evilproducer

Here is the Carrara IK bike ride!
http://youtu.be/fl5mq9Sdpwc

kakman

evilproducer said:

Here is the Carrara IK bike ride!
http://youtu.be/fl5mq9Sdpwc

That turned out great!

Details, please.

evilproducer

I was asked quite awhile ago to write up a tutorial for the Carrara Cafe of a subject of my own choosing. I'm debating doing a tutorial for this. There are still some kinks I need to work out in my workflow, but maybe tomorrow I can work up a mini tutorial.

In a brief nutshell, I used the Ten Speed model from the Objects browser and scaled it up a huge amount, parented a target helper to each of the pedals and added a .5 turns per second spin modifier to the sprocket and pedals. Every quarter turn I manually adjusted the pedal so that it kept the same general orientation. I then posed V4 roughly to look as if she were riding a bike, and then chose V4's foot, and enabled IK tracking. For the right foot, I chose the target helper for the right pedal and for the left foot, I chose the target helper for the left pedal.

I played around with changing the constraints on the foot joints (ankle) but I'm not sure that's required. I also applied target helpers to the handle bars and set the hands to track those. I did need to change the constraints on the hands (wrists) to be able to get them in the right position without distorting the rest of the arm.

kakman

Evil:

Thank you very much for the explanation of the process you used. This will give me some new things to try and experiment with.

I truly appreciate your time and effort.

By the way, I like the detail you provide when you explain things and I think that your rationale about the range of the forum reader’s knowledge and expertise is spot on. I know that I am always learning new things in this forum.

Thanks again,

Kevin

bdproductions

evilproducer said:

What you can do, as dart mentioned, is to insert a target helper object (or any object really) and select the feet to track that object. The advantage of the target helpers is that they're a little wire frame cross hairs that do not show up in the final render.

I'll post a couple screen shots in a bit. I'm in the middle of rendering some crap.

EvilProducer Thank you very much for the information in this thread. It worked exactly as you said, and what i had hoped for. I will be be posting a step by step of the process that iI used in the Music Video and ad in a few weeks. Thanks again!

evilproducer

That is cool. I'm glad it worked. I remember now that I forgot that bike tutorial. D'oh! I have some irons in the fire at the moment, but as soon as I get a little more time, I'll work something up for those that are having problems or would like a more illustrated description of the process.

Mythmaker

Just bump this very useful tip up. EP you leave all sorts of gems everywhere!

I particularly like your picture-rich tuts. I just went through SickleYield's rigging tut in PDF form, which showed that well thought out words and ample picture guides can be as effective as video tutorial. Ever consider making bite-size features-specific PDF tutorial for intermediate Carrara users?

evilproducer said:

Since it sounds as if you've used functions like I'm describing, I'll off this caveat: Carrara does not have a pin feet to the floor type command or function. The closest that I am aware of is using tracking and helper objects. There may be ways of doing it, but I haven't worked out how.

So, what I do is drop in a target helper object. There's a bulls eye icon at the top of the Assembly Room window. If I want to lock the feet, I position it over my foot. Keep in mind the hotpoint for the foot is the ankle joint, so position the target helper over the ankle.

You can adjust the size of the target helper and its color in the target helper's effects tab. If you want a target for both feet, you can either add a new one or use the Duplicate command under the Edit menu. I also rename the targets in the target helper's General tab, to something like, R foot Target and L foot Target, just to keep things straight.

Next, select one of the feet in the figure's hierarchy and select the Modifiers tab. You should see the Inverse Kinematics modifier with the option to choose an object to track. Click the icon and select the appropriate target helper. You can also select the option to track the object's orientation. This may provide a little more control keeping the feet locked in position.

A little added tip that I figured out recently is that if you change the constraints of the foot joint to Ball joint, and use Track Object Orientation, you get a near perfect pin to the floor. If you drag the hip to the point where you exceed the length of the limb then Carrara will do its best to keep the foot tracking the target, but it won't stay pinned.

You can also keyframe the tracking, by enabling and disabling the Enable checkbox over the length of the timeline.