problem.c4d

Here's the file again, it expired: https://we.tl/t-m7yeyuVukBqWPvnZ

Hi Noseman,

Welcome — and thanks for stepping in for Dr Sassi! Looking forward to learning from you and really appreciate you taking the time to help the community here!

I just have a quick question I was hoping you could help with regarding pyro.

I have a pyro flame inside a sphere and I just want it to collide with the inner surface of the sphere so it can swirl around and look cool. I made the sphere a collider and it kind of works. However, no matter what I try (increasing substeps, collision thickness, slowing down particles etc) I can't stop some of the flames from escaping, part of it always goes though.

Any idea what im missing or how to get the collisions to work correctly?

Here's my project file: https://we.tl/t-r1YDAjYNVSJwZAUm

Thanks again and have a great Easter!

Hi Dr. Sassi,

I just wanted to say a huge thank you for everything you’ve done over the years. The amount of time and care you’ve put into helping the community is honestly incredible — 30,000 questions answered is no small feat!

On a personal note, I’m especially grateful for how fast you always replied — even on holidays which was above and beyond!

You’ve helped shape so many artists (myself included), and the Cineversity community won’t be the same without you. I truly wish you all the best with your new endeavors and whatever comes next — I have no doubt you’ll make a big impact there too.

Thanks again for everything, and all the very best.

Thanks again for that, more interesting setups!

That's a great method, I didnt try xpresso! AI told me to use Cappucino but that also didnt work for me.

I ended up getting the Alembic to work in the end, I just had to play around with the settings until I had the right combination which took forever. Shame there's no super easy way to do it.

Will definitely check out your course too, looks like some prety advanced stuff, thanks for that.

Cheers!

Hi Dr Sassi, hope you're having a great start to 2026!

I'm sure I've been able to do this in the past, but Im trying to bake the animation of an object that is being driven by effectors as keyframes.

I've tried 2 different methods , a CLoner driven by Effectors, and the object driven by effectors (Object deformation mode)

I tried to cach, bake as alembic, and bake object in the time line, and messed around with connect object, but it always bakes only the PLA, but I just want the Position/ Rotation.

Surely there's an easy way to do this Im missing.

Here's my basic setup with the 2 options - https://we.tl/t-tOTIqNtUUq

Cheers!

UPDATE: I did actually get this to work in the end by giving the cloner or object a cloth tag and 100% mix animation, can then bake the sim and get the POSITION / ROTATION, but thats such a long convoluted way of doing it, you must know a better way

Thanks for these Dr Sassi, I ended up doing this with the Reeper plugin. These are really great alternatives though, never would have thought to use the random effector on the curves! I'll definitely come back to these setups/ Thanks again and sorry for the slow reply. All the best for 2026 to you too!

Hi Dr Sassi, hope you're well.

I'm make a piece of thread travel along a path like 4 seconds into this animation: https://www.youtube.com/shorts/L4B6Agk_NbA?t=5&feature=share

I was able to curl some hair around a helix, then using a line I also have hair running lengthways through the thread where it frays a little at the end - so basically I have 2 hair sets.

I then tried spline wrapping both together and along another helix - but no matter what I try it just wont wrap correctly.

The curled hair seems to wrap ok but when I add offset along the helix its a bit funy.

But the line wont wrap at all, it just keeps freaking out.

Is this a limitation of hair or is there a better way to do this to keep the curled and frayed parts but have the whole thread travel along a path?

Here's my file so far: https://we.tl/t-iCYOf4sBql

Have a great new years if I dont hear from you before!

Awesome, thanks again for that and have a great Christmas and new years (if you dont hear from me again before!)

I ended up using edges for the project, I thought I tried every cobination of settings, but great to know it actually works in a cloner on polygons!

Shame there isnt just a simple constraint you can use for this kind of thing, makes it kinda complicated when doing a lot of objects.

Thanks again Dr Sassi!

I tried parenting it to an edge instead and it works fine. Looks like the normals in a cloth sim are fine on edges - weird that polygons get messed up though

Looks like the moving mesh (which was a cloth sim) is the problem - for some reason the normals flip randomly in the sim itself

here's just the original plane sim, you can see if you select any polygon that the normals freak out during the sim. https://we.tl/t-oyCm5fWeg2

Do you know if thats something that can be fixed? Or do polygon normals always go crazy in a cloth sim?

Cheers, basically Im trying to make a popup book - I want the page to turn (deform) and some paper objects pop up attached to the surface of the page.

Using the Cloner method almost works but as you can see in my project, it flips around strangley at the start

https://we.tl/t-0VUqoubtzG

I've baked the popup animation as keyframes, but the rotation seems to go crazy when it travels along with the mesh.

Any idea if there's a better way to stick objects to a page like this: https://youtu.be/1jxodEBzsRc

Cheers, I mean it needs to stick to the polygon and move along with it as the mesh moves and deforms, so it needs to be locked to the surface not just placed there

Hi again Dr Sassi,

Do you happen to know if its possible to parent a Null to the center of a polygon on a deforming mesh?

I can get it working with a Cloner or Matrix, but I was wondering if there was an easier way with Xpresso or Constraints.

I can constrain to Points with Xpresso and Constraints and to a polygon, but I cant get the Null to align to the polygon normal and have it stick while rotating.

Here's my test file, any ideas if its even possible? https://we.tl/t-5fPW19qO3C

Thanks again!

Awesome, thanks for that, worked like a charm! Been a while since Ive needed to rig something like this up, this work flow makes life much easier! Cheers!

Hi Dr Sassi,

I'm trying to rig the spine of a book to open using joints and weighting.

I've painted in some weights with the Weight Tool and intend to smooth it out. But there's a few weighted points I'd like to set back to 0 weighting as they poke out when adjusting the joints - but no matter what I do I just cant seem to remove the weighting with the weight brush.

I tried many different modes - I would think subtract mode, or setting absolute mode to 0 and painting would work but it doesnt seem to do anything on the points, sometimes it even adds to the weighting. I also thought holding CTRL and painting would work which is what Chat GPT recommended - but it doesnt work.

Do you know what the steps would be to remove the weghting on the wrong points by painting?

Here's my file so far: https://we.tl/t-6lejxCn0rX

Thanks again!

Yes you're right! Moving those broken keys seems to fix the problem. The bake must have messed up the keyframes - I just used a track modifier for the bounce originaly. Weird that it looks fine without the cloner.

you've done it again, thanks for that! Now I can finish this one off, cheers!

No worries, I did the test but I dont understand why that matters. On every frame mode in the timeline it should force it to perform the calculations shouldnt i? so if I do a mograph Cache it should work, but it still glitches. Are you saying it works fine for you and that it must just be my computer? I never would have thought it could be a hardware issue

cv4_2026_drs_25_mgta_11:

Frames: 301
Total time: 0.950
FPS: 316.91

Test001:

Frames: 81
Total time: 2.189
FPS: 37.00