tyFlow Forum
tyPush "Push Splines" does not respect Spline Influence soft-selection - Printable Version

+- tyFlow Forum (https://forum.tyflow.com)
+-- Forum: tyFlow Discussion (https://forum.tyflow.com/forum-1.html)
+--- Forum: General Discussion (https://forum.tyflow.com/forum-2.html)
+--- Thread: tyPush "Push Splines" does not respect Spline Influence soft-selection (/thread-5023.html)

tyPush "Push Splines" does not respect Spline Influence soft-selection - YOHEI MIYAHARA - 11-26-2025

Hi,
I’m testing tyPush (Push Splines) together with Spline Influence in 3ds Max, but I’m running into unexpected behavior.
What I’m trying to achieve
I want to:
Quote:Use Spline Influence to create a soft selection on a spline,
then use tyPush to push only that influenced area.
Basically: sphere affects part of the spline → only that area should deform.
Modifier stack

Code:
Editable Spline 
→ Normalize Spline 
→ Spline Influence 
→ tyPush (Push Splines / Simple or Clip)
What actually happens
  • The soft selection from Spline Influence is correctly passed up the stack
    (verified using an XForm modifier, it reads the selection properly).
  • However, tyPush seems to completely ignore the influenced selection and instead:
    • Pushes the entire spline.
    • Endpoints move abnormally far (sometimes exploding or folding).
    • Some knots don’t move at all, regardless of the influence.
    • Sometimes the whole spline shifts upward globally.
Additional notes
  • The spline is an open spline (not closed) – more like a cable/rope/tentacle.
  • Tested both Simple and Clip modes in Push Splines.
  • Knot types were tested with Bezier and Corner.
  • Selection clearly works for XForm, but tyPush doesn’t seem to respect it.
  • It feels like tyPush’s spline mode is optimized for closed shapes rather than open splines.
Question
Is this:
  1. A limitation of tyPush’s spline implementation?
  2. A known bug with soft selections on shapes?
  3. Or am I missing a required setup step?
If possible, is there a recommended way to use tyPush together with Spline Influence for deformations on open splines?
Thanks!

RE: tyPush "Push Splines" does not respect Spline Influence soft-selection - tyFlow - 11-27-2025

It would be best if you could post a scene file where you're experiencing the issues.

tyPush - Spline/simple mode doesn't currently take selections into consideration - that's correct. If you post a scene with your setup and desired result, I can take the issues you're seeing into consideration when updating the modifier.

RE: tyPush "Push Splines" does not respect Spline Influence soft-selection - YOHEI MIYAHARA - 12-02-2025

(11-27-2025, 02:26 PM)tyFlow Wrote: It would be best if you could post a scene file where you're experiencing the issues.

tyPush - Spline/simple mode doesn't currently take selections into consideration - that's correct. If you post a scene with your setup and desired result, I can take the issues you're seeing into consideration when updating the modifier.

Hi Tyson,
Thanks again for your reply earlier.
As requested, I prepared a small scene file demonstrating the issue I'm experiencing when using tyPush → Push Splines together with Spline Influence on an open spline.
Environment:
  • tyFlow 1.131
  • 3ds Max 2024
Current understanding of the implementation
After reviewing the documentation, my understanding is:
  • Use vertex selection applies only to Push vertices
  • Currently, Push Splines (Simple / Clip) does not take knot selections, soft selections, or Spline Influence weights into account
So the behavior I’m seeing appears consistent with the current specification.
I just want to confirm whether Push Splines is intended only for full-spline offsets, without partial deformation support.
What the scene demonstrates
Right side – Expected behavior (with XForm)
  • Spline Influence generates a correct soft selection on the open spline
  • XForm applies deformation only to the influenced knots
  • Moving the Influence Helper shifts the deformed region smoothly
Left side – Actual behavior with tyPush
  • Simple mode: pushes the entire spline, ignoring the influence
  • Clip mode: spline collapses or breaks unpredictably
  • End knots move excessively or invert
    → This confirms that tyPush currently does not evaluate spline knot selection or weights.
Feature request / question
For workflows involving ropes, cables, tentacles, and other deformable open splines,
being able to push only the influenced section of a spline (e.g., based on Spline Influence weights) would be extremely useful.
Is partial spline deformation something that might be supported in a future update,
or is Push Splines intended to remain a full-spline offsetting tool?
Scene contents
  • Open spline
  • Normalize Spline
  • Spline Influence (Sphere)
  • XForm (shows expected result)
  • tyPush (Simple / Clip)
  • Influence Helper for visualizing the difference
If you'd like, I can prepare additional examples (closed splines, multi-segment splines, etc.).
Thanks again for your time and consideration!

RE: tyPush "Push Splines" does not respect Spline Influence soft-selection - tyFlow - 12-03-2025

Thanks for the file - selection-based spline tyPush will be available in the next build.