OBJECT_OT_shape_key_clear ignores slider_min and slider_max #109011

New Issue

Thomas Barlow · 2023-06-15T15:46:54+02:00

Thomas Barlow commented

2023-06-15 15:46:54 +02:00

System Information
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: NVIDIA GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 531.41

Blender Version
Broken: version: 2.79, 3.5.1, 4.0.0 Alpha, branch: main, commit date: 2023-06-03 14:21, hash: ab6860f3de0f
Worked:

Short description of error
The OBJECT_OT_shape_key_clear operator clears the .value of each Shape Key, setting it back to zero, but Shape Keys have .slider_min and .slider_max attributes which specify the minimum and maximum values for .value. OBJECT_OT_shape_key_clear does not respect the .slider_min/max values when it clears the .value of each Shape Key, setting .value to an otherwise impossible value when either .slider_min is greater than zero or .slider_max is less than zero.

Exact steps for others to reproduce the error
Attached is a .blend (authored in 4.0.0a) with steps 1-4 already set up.

Create two non-'Basis' shape keys on a default cube
On the first shape key, set its .slider_min to 0.5
On the second shape key, set its .slider_min to -1.0
On the second shape key, set its .slider_max to -0.5
Click the button in the UI to Clear Shape Keys, or run bpy.ops.object.shape_key_clear()
Observe that the .value of each shape key is now set to 0.0

**System Information** Operating system: Windows-10-10.0.19045-SP0 64 Bits Graphics card: NVIDIA GeForce GTX 1070 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 531.41 **Blender Version** Broken: version: 2.79, 3.5.1, 4.0.0 Alpha, branch: main, commit date: 2023-06-03 14:21, hash: `ab6860f3de0f` Worked: **Short description of error** The OBJECT_OT_shape_key_clear operator clears the `.value` of each Shape Key, setting it back to zero, but Shape Keys have `.slider_min` and `.slider_max` attributes which specify the minimum and maximum values for `.value`. OBJECT_OT_shape_key_clear does not respect the `.slider_min/max` values when it clears the `.value` of each Shape Key, setting `.value` to an otherwise impossible value when either `.slider_min` is greater than zero or `.slider_max` is less than zero. **Exact steps for others to reproduce the error** Attached is a .blend (authored in 4.0.0a) with steps 1-4 already set up. 1) Create two non-'Basis' shape keys on a default cube 1) On the first shape key, set its `.slider_min` to 0.5 1) On the second shape key, set its `.slider_min` to -1.0 1) On the second shape key, set its `.slider_max` to -0.5 1) Click the button in the UI to Clear Shape Keys, or run `bpy.ops.object.shape_key_clear()` ![image](/attachments/130c5fd7-b187-4674-8cb7-90b03296f2e9) 1) Observe that the `.value` of each shape key is now set to 0.0

image.png

46 KiB

shape_key_clear_slider_min.blend

100 KiB

Thomas Barlow added the

labels 2023-06-15 15:46:55 +02:00

YimingWu commented

2023-06-16 04:41:01 +02:00

I can confirm that. From the description I guess the expected value should be 0.5 and -0.5 (as in 0 clamped by slider_min and slider_max) ?

The slider is more about restricting the value on the interface. OBJECT_OT_shape_key_clear operator may intend to reset everything to zero so you can see the original mesh, if you have a min/max value that doesn't cover 0, the suggested behaviour would not reset everything to zero and some layers will still have influence to the original mesh, this might lead to confusion.

Maybe an option can be added to the operator that allows it to respect min/max values.

I can confirm that. From the description I guess the expected value should be `0.5` and `-0.5` (as in 0 clamped by `slider_min` and `slider_max`) ? The slider is more about restricting the value on the interface. `OBJECT_OT_shape_key_clear` operator may intend to reset everything to zero so you can see the original mesh, if you have a min/max value that doesn't cover 0, the suggested behaviour would not reset everything to zero and some layers will still have influence to the original mesh, this might lead to confusion. Maybe an option can be added to the operator that allows it to respect min/max values.

YimingWu added

Module

Animation & Rigging

Status

Needs Info from Developers

and removed

Status

Needs Triage

labels 2023-06-16 04:41:25 +02:00

Thomas Barlow commented

2023-06-16 06:17:42 +02:00

0.0 clamped by slider_min and slider_max would be what I expected because that matches what happens when you try to set the value directly to 0.0 with the Python API, or when setting "value" with foreach_set.

If the slider_min and slider_max instead acted like a soft_min and soft_max whereby values outside of the slider range could be entered manually, then I think it would be fine for the operator to set the values to zero. A soft range would certainly make Python scripts that need to set specific shape key values less of a pain so that there's no need to check for weird slider_min and slider_max values, but I unfortunately suspect it would break drivers on shape key values that rely on the min and max values.

I would agree that it's questionable whether the operator is achieving its intent if it doesn't set all the values to zero.

`0.0` clamped by `slider_min` and `slider_max` would be what I expected because that matches what happens when you try to set the `value` directly to `0.0` with the Python API, or when setting `"value"` with `foreach_set`. If the `slider_min` and `slider_max` instead acted like a `soft_min` and `soft_max` whereby values outside of the slider range could be entered manually, then I think it would be fine for the operator to set the values to zero. A soft range would certainly make Python scripts that need to set specific shape key values less of a pain so that there's no need to check for weird `slider_min` and `slider_max` values, but I unfortunately suspect it would break drivers on shape key values that rely on the min and max values. I would agree that it's questionable whether the operator is achieving its intent if it doesn't set all the values to zero.

YimingWu commented

2023-06-16 08:18:17 +02:00

If the slider_min and slider_max instead acted like a soft_min and soft_max whereby values outside of the slider range could be entered manually, then I think it would be fine for the operator to set the values to zero.

Yeah, it seems to be a inconsistency there, while you can't manually set 0 if it's outside the min/max range, the operator does do that.

> If the slider_min and slider_max instead acted like a soft_min and soft_max whereby values outside of the slider range could be entered manually, then I think it would be fine for the operator to set the values to zero. Yeah, it seems to be a inconsistency there, while you can't manually set 0 if it's outside the min/max range, the operator does do that.

YimingWu commented

2023-07-05 06:42:01 +02:00

Looks like no one is looking at this thing due to other higher priority isues, I guess I'll make a patch.

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OBJECT_OT_shape_key_clear ignores slider_min and slider_max #109011