desperately needed tool

protovu

I am a Carrara dedicated user since Raydream....yes, Raydream. What a great app it has been. But I desperately need a particular tool. Cinema 4D , Maya, Blender, Modo , etc. all have the ability to easily and precisely deform a vertex object along a spline path, or free form line. There are some deformers in Carrara which allow an approximation of this function , but when one needs to animate an object precisely along a really tortuous, compound curve, for example, a micro catheter within vasculature in the form of a double twisted "S" ,
frustration awaits. Using more than one bend and twist, or using a wave deformer combined with bend and twist, can get one in the right direction, but this technique provides only a cumbersome, time sucking approximation of what is needed. Worse, often I have needed to change my anatomy model to enable the travel of the medical device. Fenric's plugin has not proved useful here.
With the above in mind, is there anything in the works for Carrara which will help with this problem? See http://www.lynda.com/CINEMA-4D-tutorials/Deforming-objects-Spline-Wrap/73931/78012-4.html?vid=2&type=2 for an example of the ease of control and versatility I have been needing in Carrara.

evilproducer

I don't think Carrara has that tool, but there may be a couple ways yo haven't thought of. Keep in mind, I haven't seen your scene so I can't really try to approximate it.

The spline modeler in Carrara can be animated, so you may be able to do something with that. The caveat is that you can't edit in the assembly room which can be a PITA. You can however, edit a vertex object, but not animate it unless you've built in morphs. You could design your scene in reverse by visualizing how you want the spline object to move, animate it, then in the Assembly room build the object the spline object is supposed to move through.

Another possibility is a rigged object with key bones in the rig set to track target helper objects.

There may be other ways to do this, but I'm not sure if they're as elegant as the tool you described. You could submit a feature request through DAZ 3D's Zen Desk (or whatever they call it).

protovu

Hi Evil,
Thank you for replying. I have been down the spline modeler road. Does not work. Think " snake". My object must navigate a path without distorting, except
for the constraints of the path itself. Additionally, with the spline modeler, the modeled characteristics of the device are limited. Often a client device is pretty elaborate.
As a vertex object, it can navigate, and articulate in precise ways.

Bones.....Been there too. Bones, even with the Fenric do not like snaking. Fenric's plugin is good for a creature, perhaps, but not for a device.

For my scene, just imagine a scope with an elaborate head navigating through a pretzel.

I have cheated:
Used shaders to grow a catheter, cheating the head of the device every other frame.
Used deformers to the limits of their abilities....taking hours and hours to do something other apps do in minutes.

evilproducer

Th only thing I can suggest would be a feature request. It's a bummer you have to go through that.

Design Acrobat

protovu said:

Hi Evil,
Thank you for replying. I have been down the spline modeler road. Does not work. Think " snake". My object must navigate a path without distorting, except
for the constraints of the path itself. Additionally, with the spline modeler, the modeled characteristics of the device are limited. Often a client device is pretty elaborate.
As a vertex object, it can navigate, and articulate in precise ways.

Bones.....Been there too. Bones, even with the Fenric do not like snaking. Fenric's plugin is good for a creature, perhaps, but not for a device.

For my scene, just imagine a scope with an elaborate head navigating through a pretzel.

I have cheated:
Used shaders to grow a catheter, cheating the head of the device every other frame.
Used deformers to the limits of their abilities....taking hours and hours to do something other apps do in minutes.

taking hours and hours to do something other apps do in minutes - That's my life in a nutshell.

cdordoni

Faba has done a lot with Carrara (and Blender) and rigging and she may have some ideas on how to do this.

http://www.daz3d.com/forums/member/38226/

Roygee

Haven't seen the model you need to move, so don't know how amenable it would be to this method - to use it, you would need to be able to make it in parts.

Looking at the video, you could certainly do everything shown there in Carrara using motion paths - in fact, this video took me less time to set up than it took to watch the video!

http://youtu.be/wXCOhRaaqiU

protovu

Hi Roygee,
Little balls on a motion path work well, but are not related to what is needed here. Please see the pdf at the link below to see what is needed.

http://www.protovu.com/snakethrough/

Hi Cdordoni,
Thanks, I will check in with Faba.

Dartanbeck

I wonder how it would work to set up a simple rig from head to tail, set them as ball joints, and turn on collision. Wow, I'm glad it's not me that has to ache over such a thing.

Eric3ddd

2 suggestions (untested):
• Bones and physics/collision detection to keep the catheter inside the artery. You can keep the tip of the catheter unboned or completely linked to first bone so it doesn't distort.
• Animate just the tip of the catheter using motion path and composite the tube in After Effect or similar. The tick marks would not animate though.

Good luck!

protovu

Hi Dartanbeck,
I have spent many hours doing what you have described......with completely unsatisfactory results. Think of how each bone/vertex segment needs to precisely replace the position of its preceding segment, without affecting its children. Nightmare to do, believe me. This led me try the Fenric ERC, another unfortunate endeavor.
The Fenric plugin would be great if I were animating a swimming organism.

Hi Eric3ddd,
I have used your second bullet point. As you note, it is limited in that the catheter itself cannot be animated, but is merely a shader growing over a length of tubing.
No tick marks. Really cumbersome, labor intensive animation on the tip, too.

I have not tried your first bullet point. I will give it a shot. Note, though I often have very tight fits in the arteries, so I suspect I will be getting stuck...literally.

protovu

At least for me, bones do not respond to collision detection.

3DAGE

You should be able to set up a scene using some proxy physics objects, to give you the motion, then use tracking to have the rigged model (bones) follow each of the tracked proxies.

See quick Scene file... (using Bullet physics in C 8.5) ..

https://dl.dropboxusercontent.com/u/7907045/C85_Physics_tube_drag.car

Bullet physics can work with constraints, and doesn't need bones, you just need to create a simple parent / child hierarchy.

The First Proxy (main parent) uses key-framed motion, to animate it's movement through the tube.(manual key-frame animation)
the other proxy objects (children) all use Physics motion, and have a Ball-Joint constraint, with the Physics effects set to no bounce / no friction. and since they're parented to the main parent proxy, they follow it through the tube.
Turning off the default Scene / Physics / Gravity,. also helps,. a lot.
if you need gravity,. use a direction force, as the strength of that can be animated as needed.

Once you have that physics motion for each proxy object, then you can apply a tracking modifier to the bones in your rigged Catheter model, and tell each bone to track the proxies. and Hide the Proxy objects for rendering

Note: this is a medium scale scene,. done quickly,. your scene may differ ;)

Hope it helps. :)

protovu

Thank you, 3Dage,
Very kind of you to take the time to make this file.
This is a technique I have tried with target helper objects, and similarly with the Fenric plugin. Do you see the way the balls jitter and dance as they
navigate the tube? A catheter with bones similarly dances. What has worked best to date has been to use multiple bend and twists modifiers which are in
advance of the path of the vertex object, or group. Then I can "push" the vertex object smoothly through its lumen. The problem, of course, is that the bend and twist
modifier does not really like to distinctly partition a long vertex object. The "limits" interfer with each other it seems. In the file I have uploaded (dermercathtravel.car), you will see that the
second bend shortens the device....not good. I really want to simply describe a path, and have the device follow it.

http://www.protovu.com/snakethrough/

faba

Did you have something like this in mind?

edit: looks like it doesn't like animated gifs.
Check your PMs please

protovu

Thank you, Faba.
I have reponded via the PM.

Denki Gaka

I don't use carrara, but if I had to do something like this in one of my games I would simply animate the texture that is wrapped around that tube/vein to show the catheter moving up it and then animate the probe head to move in front of the texture. That way you could take a straight tube and strait catheter and create your animated texture by moving straight up and then apply it to the twisty tube for when you animate the probe head. Just my thoughts.

Dartanbeck

mccarlp said:

I don't use carrara, but if I had to do something like this in one of my games I would simply animate the texture that is wrapped around that tube/vein to show the catheter moving up it and then animate the probe head to move in front of the texture. That way you could take a straight tube and strait catheter and create your animated texture by moving straight up and then apply it to the twisty tube for when you animate the probe head. Just my thoughts.

Beautiful plan.
For the actual mesh of the following tube, just add thickness to the existing one and separate them. Then apply the animated texture.

protovu

Yes, that is a work around I have done many times through the years. It is restricted on many levels. If the tube has any sort of ribbing, then it appears to "grow" rather than advance. And the tip, or "probe" requires hours of tedious keyframing to realistically navigate.

3DAGE

HI protovu :)

I admit the Physics simulation is very rough, and there's a lot of unwanted "jitter"
But,... Physics motion can be converted to Key-frame animation,. that should allow you to selectively delete some of the keys, and smooth out the motion.
just change the motion type from Physics to Keyframed.

Also, by refining the physics settings, and possibly the objects shape/density, I think that would help get a smoother motion.

Hope it helps :)

protovu

Thanks, 3dage.
I will look at trying this....but bottom line:
It seems like this function , having a vertex object snake along a path, is worthy of something more than a work around.
It is, after all, available in virtually every animation bundle out there. I am hopeful that Daz will consider either a new tool for Carrara,
or a modification to the existing "bend and twist" deformer.
Thanks again for your suggestions. If anything comes of it, I will post.

3DAGE

I agree, there are several "small things" which could be added to carrara to make things easier to do,.
such as a Helix path "primitive" in the vertex modeller,. simple and really useful for many different things,, from screw's to spiral stairs.

I like the concept of positioning different bend/twist modifiers in the scene space, and the object's being effected as it / they,. pass through those deformers,. rather than the deformer being applied to the object, and only using the Objects local space,

I'd also like to see deformers and Physics being able to work together., currently the physics only handles the shape of the unmodified object. ...animated modifier distortion of the mesh has no effect on the physics.

It's always worth adding a feature request.

:)

protovu

Yes, indeed. I have requested. The helix path sounds nice. I have cheated from the spline modeler to do this....you probably have too. That is,
spiral in spline
edit in another modeler(vertex)
in vertex modeler, select edges that follow the helix
sweep a shape along the edges.