Maniphest T76891

Simple Deform Modifier - Bend Mode not consistent
Closed, Duplicate
Actions

Assigned To
None
Authored By
No Thanks (emptyhead41)
May 19 2020, 7:08 PM
Tags
  • BF Blender
Subscribers
Brecht Van Lommel (brecht)
No Thanks (emptyhead41)

Description

System Information
Operating system: Windows-10-10.0.18362-SP0 64 Bits
Graphics card: GeForce GTX 980/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 445.75

Blender Version
Broken: version: 2.82 (sub 7), branch: master, commit date: 2020-03-12 05:06, hash: rB375c7dc4caf4
Worked: (optional) possibly never

Short description of error
Bend mode is not performing consistently

Exact steps for others to reproduce the error
Apologies for posting again, but my previous report was closed without any discussion. I'd like to try and clarify how the Simple Deform modifier isn't working correctly when using the Bend mode.

The behaviour looks like a bug as it does not act consistently. I would welcome someone explaining the behaviour for the following scenarios particularly what is happening in the scenarios where one plane of the mesh rotates instead of the entire mesh bending.

Steps:

1.1 Create a Mesh that extends along X axis

1.2 Apply Simple Deform modifier>>Bend on Y axis -45 degrees


Bottom of mesh doesn't move, top of mesh is rotated -45 degrees around mesh origin on Y axis

1.3 Bend on Y axis -90 degrees


Bottom of mesh hasn't moved, top of mesh is rotated -90 degrees around mesh origin on Y axis

1.4 Select Z axis on Bend mode. Set to 45 degrees


Mesh bends around mesh origin on the Z axis. This is expected behaviour and different to what happens 1.2 and 1.3

1.5 Bend on Z axis 90 degrees


Mesh bends around mesh origin on the Z axis. This is expected behaviour and different to what happens 1.2 and 1.3

2.1 Construct a Mesh that extends along Y axis

2.2 Apply Simple Deform modifier >> Bend mode on X axis -45 degrees


Bottom of mesh unaffected, top of mesh rotates -45 degrees on X axis

2.3 Bend on X axis -90 degrees


Bottom of mesh unaffected, top of mesh rotates -90 degrees on X axis

2.4 Select Z axis and set to -45 degrees


Left hand side of mesh unaffected, right hand side is rotated -45 degrees on Z axis

2.5 Bend on Z axis -90 degrees


Left hand side of mesh unaffected, right hand side is rotated -90 degrees on Z axis

3.1 Create a Mesh that extends along Z axis

3.2 Apply Simple Deform modifier >> Bend mode on X axis 45 degrees


Mesh bends on X axis. Expected behaviour. Same as 1.4, 1.5, but different to 1.2, 1.3, 2.2, 2.3, 2.4 and 2.5

3.3 Bend mesh on X axis 90 degrees


Mesh bends on X axis about 90 degrees. As 3.2

3.4 Bend on Y axis 45 degrees


Mesh bends on Y axis. Expected behaviour as 3.2

3.5 Bend on Y axis 90 degrees


Mesh bends on Y axis about 90 degrees. Expected behaviour as 3.2

Inconsistent behaviour in Bend mode. Half of the possible selections result in bending the mesh as would be expected, the other half result in one plane of the mesh being rotated.

Please before closing could it be discussed how this can be explained as expected behaviour?

Event Timeline

No Thanks (emptyhead41) created this task.May 19 2020, 7:08 PM
Brecht Van Lommel (brecht) closed this task as a duplicate of T76838: Simple Deform Modifier - Bend Mode.May 19 2020, 8:43 PM
No Thanks (emptyhead41) added a comment.May 19 2020, 11:10 PM

Guys, I appreciate that you all work on this for no financial reward and we get to use software for free, but all I asked was to leave this open to discussion before closing it down.

I took time to try and demonstrate as clearly as possible why I felt this was a bug. Clearer than it was put across in the other report. It can be seen in the screenshot that the behaviour is inconsistent. It's not that the feature is confusing to use, or that there isn't enough control options. The feature is simple. Itworks correctly if the mesh extends along X or Z. If it extends along Y then one plane gets rotated. There's no bending happening.

I understand that you feel differently and that is why I requested that the report be left open to discuss, so that either the logic of part of the mesh being rotated is explained or otherwise.

I understand it's frustrating to have to deal with bugs being reported that obviously aren't bugs, but please do me the decency of at least acknowledging and addressing points which appear valid and showing why they're not valid instead of just closing my reports down.

Brecht Van Lommel (brecht) added a subscriber: Brecht Van Lommel (brecht).May 19 2020, 11:31 PM

I replied in the other task. It's not necessary to create a new bug report right after the other one was closed, discussion can still happen in that closed bug report instead of being duplicated in two places.