Tearing a cloth with a clean cut

[history-growth]

Hi,

looking for a way to tear a cloth object with a clean cut - as if it was cut by a knife. Finding it hard to direct how the tearing is happening on the cloth object.
The approach I'm testing right now is to assign a Collider Tag to a hidden object and having it create a vertex map on the cloth object that affects the tearing.

Any suggestions on how to create a clean and precise cut (imagine using a sharp knife on the cloth) and then having the cloth slightly folding up?

Attaching my scene file as reference

tearing knife.c4d

[Dr. Sassi]

Hi history-growth,

Would you mind checking the attachment? It gives me an error message.

Cheers

[Dr. Sassi]

P.S.: Perhaps that could be a start?
https://stcineversityprod02.blob.core.windows.net/$web/Cineversity_Forum_Support/2023_PROJECTS_DRS/20230305_CV4_2023_drs_23_SIcc_01.c4d.zip

Besides that, PoseMorph comes to mind, so it is more under control.

[history-growth]

@Dr-Sassi excellent solution. I'm guessing the linear field and box field approach works so much better since it's not trying to generate a map based on proximity to the polygons but rather just use the linear field?

[Dr. Sassi]

Hi history-growth,

A clean cut is perhaps more challenging than a chaotic tear. I'm not pretending that I have done it with the new Cloth in any production. So, my example follows the parameters and how to supply the information to the system—my best result from last night's exploration.

You are guessing correctly; the path of points and the combination with the Linear field is the key. I explored if more considerable distances or shorter ones 90º to the cut are better.

I find Dynamics/Simulations undoubtedly intriguing but more challenging to art direct. Sometimes I use the results of the dynamic (point cached) to harvest certain states and then use them as "Blend-Shapes" in a Pose Morph. This is a nice balance between the two qualities.

All the best