Scaling problem while rotating a selection
Posted: 18 September 2020 08:39 PM   [ Ignore ]  
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I want to animate the opening and closing of this cardboard box. After selecting the lid’s points, set selection, moved the axis to the back edge (the hinge) I recorded the closed position (f1) and fully open (f250). The lid starts off in its natural state, shrinks in Y and then expands. Is this workflow totally wrong or am I missing something? Please help -:) Cheers/ Anders

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Posted: 18 September 2020 09:35 PM   [ Ignore ]   [ # 1 ]  
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Hi Anders,

In the way you describe it, it is not really how it works.

What you have rotated was the selection based axis. What you need to rotate is the Object axis. (If the lid is an object on its own).

There are many ways to open a lid with points move only. PoseMorph, while using Rotational and define a specific axis, or using a Cluster Object and use a parent for the points as the axis.

Scene file and screen capture
https://www.amazon.com/clouddrive/share/E4BLuWk4uwq0nryX6WHRALKOXEs5ELAGAoq5T7XAywu

What you have experienced, and I guess here, is the movement from one point position to the next, a straight line. It doesn’t matter how the points where moved; what matters is the information stored in the keys.

Since I consider guessing as a pretty nonprofessional behavior, I love to see a scene file, reduced to the problem typically. Images usually are not really at all helpful. Since we live in ransomware times, I use ONLY DropBox, Amazon, Adobe, Google, Wetransfer, or Apple as cloud service, with no abbreviated URLs. I can always set up an upload link if needed.

Of course, to attach a zipped file to the post is the easiest way.

All the best

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Dr. Sassi V. Sassmannshausen Ph.D.
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Posted: 19 September 2020 05:33 AM   [ Ignore ]   [ # 2 ]  
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Dr Sassi, Thanks for your quick reply yesterday evening. I have attached the file for your reference and if you find something else that could be helpful I would be grateful. I’ll start to look into Posemorph and Cluster Objects in the meantime. Yesterday was a very long day, trying to understand what I was doing wrong.

Cheers, Anders

File Attachments
OPEN:CLOSE BOX301.c4d.zip  (File Size: 213KB - Downloads: 8)
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Posted: 19 September 2020 09:24 AM   [ Ignore ]   [ # 3 ]  
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[POSE MORPH, JOINT-RIG]

Hi Anders,

Thanks for the file, which changes my reply. It is not just a lid, it also has an extra wing on the end. This is a little bit more complex; however, it can be done with no problems.

I have attached two options that I think are the primary way to do this: PoseMorph and Joint based.

Note that the central part moves the little one, so there is a specific hierarchy for the PoseMorph that needs Poses, each with its own axis (the yellow one). For the Joint based rig, this requires a few joints; the main part has a joint, the lid has one, and the “wing” has another one.

In case that sounds all unfamiliar to you, I have made a short little screen capture. It is one minute long and hopefully gives some ideas of the inner workings.
Screen-capture and files:
https://www.amazon.com/clouddrive/share/KyNy1IhITjXSKWlSOKRWoY7cHEpAi4vfIceoHMKEx7x

I would prefer the Joint based one, as it is easier to extend later on.
Weighting of Joints:
https://www.cineversity.com/vidplaylist/weight_painting/

There are certainly some questions, let me know; I’m happy to look into it.

My best wishes

P.S.: the Cluster idea would need to be created with a Null (Parent/Child) Hierarchy, so the Joint option does this naturally.

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Dr. Sassi V. Sassmannshausen Ph.D.
Cinema 4D Mentor since 2004

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Posted: 19 September 2020 10:58 AM   [ Ignore ]   [ # 4 ]  
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[CLUSTER, HIERARCHY/Parts]

P.S.: Just to share the idea of how the Cluster could work
Scene file
https://www.amazon.com/clouddrive/share/eZpcD2VpUzAcrjhqgsFWdBFP5ZfrLI49RXfi6zGtZ6S

More about this is here
https://help.maxon.net/r23/en-us/Default.htm#html/OCACLUSTER.html

Also, here, in this case, not in general, the joint set up seems to have the better set up, even it works similarly here.
With joints, we give points weight to be moved by one or more joints. With Cluster, we can connect point selection to objects.
Both have weighting options. (if an area is moved by more then one joint or Null.)
With Joints, we have a very functional toolset to manage all in one weight map. For Clusters, we need to set up a weight for each instance.
The tricky part in weighting is to have per point 100%, not more or less. Otherwise, the points would lag behind or run away, while others are moved correctly. With Joints Weights, we have a management tool for that.

======
Another method is based on the idea to separate the parts, while eventually extend some polygons where the “cut” is.

AS long as the hierarchy is well defined, the animation is quite simple. Also, here (as mentioned in post #1), each part’s object axis needs to be where the rotation point is, again, not the Rotate Tool axis. The beauty here is, it is easy to ‘read” in terms of set up; even after months, the animator is quickly back to work with it.

Example
https://www.amazon.com/clouddrive/share/7PQkG15TMH2Y6nBMWHD0KZvxPO216YAWe5sYDX2DxL4

There are more options, but typically I think three are a good amount to make valid decisions; more is better, of course.

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Dr. Sassi V. Sassmannshausen Ph.D.
Cinema 4D Mentor since 2004

Photography For C4D Artists: 200 Free Tutorials. Texture, Panorama, HDRI, Camera Projection, etc.
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Posted: 19 September 2020 01:43 PM   [ Ignore ]   [ # 5 ]  
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Hi Dr Sassi,

I’m so grateful for your help. I looked through all of the work you did to solve my problem. I only had some trouble with binding the bones to the geometry, but I blame that on ignorance, as it was the first time I attempted using this workflow. It was a completely different approach to my original idea and it works flawlessly as you can see in my attached file. I have never used this forum before, but I’ll be back if I run into problems in the future. What service you provide, even on a weekend.

FYI, the box is part of a larger scene where the viewer can look into the box. It’s bottomless and animations will pop up and reveal surprises.

I Thank You Again,

Cheers, Anders

File Attachments
OPEN:CLOSE BOX204.c4d.zip  (File Size: 138KB - Downloads: 7)
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Posted: 19 September 2020 02:27 PM   [ Ignore ]   [ # 6 ]  
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[Quick weighting rundown]

Thanks for the file, Anders.

Great start with weighting; for the first time, this is good.

Please have a look at the weight.

In your example, the side “wings” have red in them, which means they will get distorted. Etc.

Joint 1 [red] should only affect the main box.
Joint 2 [green] should only affect the lid.
Joint 3 [blue] should only affect the “wing”.
Joint 4 is just the tip, and typically without weight.

(There can be a 50/50 mix in the tiny where two elements meet, but only precisely on that axis, not much further.)

I have recorded a quick example of what needs to be fixed and how. Please note that this is a mechanical rig, with a character rig, the weighting is often more gradual, softer, to show the skin’s stretch, for example. Here we need clear islands of weighting.
Screen capture
https://www.amazon.com/clouddrive/share/DEgDL5BAW75YSh1cvNjSvc05YyiSdW3Cv6m33C8Z6t9

Joints typically get rotation keys, no position keys.

All the best

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Dr. Sassi V. Sassmannshausen Ph.D.
Cinema 4D Mentor since 2004

Photography For C4D Artists: 200 Free Tutorials. Texture, Panorama, HDRI, Camera Projection, etc.
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Posted: 19 September 2020 06:06 PM   [ Ignore ]   [ # 7 ]  
Total Posts:  7
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Dear Dr. Sassi,

At 8:54PM tonight I saved this file one more time. Granted I had some trouble, with the binding where I didn’t cmd-clicked the geometry, never figured out your selections tags and it took a while to get the colors not to bleed into each other. Please have a look at the result so far, when you have a chance:

Thank You so much for your invaluable help.

Cheers, Anders

File Attachments
OPEN:CLOSE BOX205.c4d.zip  (File Size: 138KB - Downloads: 7)
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Posted: 19 September 2020 09:23 PM   [ Ignore ]   [ # 8 ]  
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Hi Anders,

Again, thanks for the file. I love to see what you did, and where I might be able to point out something, so you will feel more confident with this.

Screen capture and file
https://www.amazon.com/clouddrive/share/v8gejA3dbw5yN3WttZewq5kHADic4urfYtN9h6276gy

Overall, things work, just tiny details that need more attention. Don’t take it as a critique, as you went very fast to a good level.
Always remember, there are no mistakes, just gained experience.

What counts that it works on end. I hope you will soon feel that it moves into muscle memory, and it is a pleasure to explore more.
I hope you enjoy your progress.

Have a great weekend.

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Dr. Sassi V. Sassmannshausen Ph.D.
Cinema 4D Mentor since 2004

Photography For C4D Artists: 200 Free Tutorials. Texture, Panorama, HDRI, Camera Projection, etc.
https://www.youtube.com/user/DrSassiLA/playlists

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