The first uv layer will be overwritten by the second uv layer #104569

New Issue

Mingfen Wang · 2023-04-25T04:02:34+02:00

Mingfen Wang commented

2023-04-25 04:02:34 +02:00

System Information
Operating system: macOS-13.3.1-arm64-arm-64bit 64 Bits
Graphics card: Apple M1 Apple 4.1 Metal - 83.1

Blender Version
Broken: version: 3.5.0, branch: blender-v3.5-release, commit date: 2023-03-29 02:56, hash: 1be25cfff18b
Worked: (newest version of Blender that worked as expected)

Short description of error
The first uv layer will be overwritten by the second uv layer

Exact steps for others to reproduce the error
This issue only appears in Blender 3.5, Blender 2.93/3.3/3.4/3.6 alpha have no issues.

If I import two uv layers via Python script, the first uv layer will be overwritten by the second uv layer, while the second uv layer has no data at all; if I only import the first uv layer, the first uv layer will be correct, so I can confirm that the first uv layer is overwritten by the second uv layer.

Here is my code:

bm = bmesh.new()
bm.from_mesh(me)
for uv in node['UV']:
uv_name = uv[0]
uv_index = uv[1]
uvs = uv_dic[uv_index]
uv_layer = bm.loops.layers.uv.new(uv_name)
bm.faces.layers.face_map.verify()
for (i, f) in enumerate(bm.faces):
for (j, l) in enumerate(f.loops):
luv = l[uv_layer]
luv.uv = (uvs[i][j][0], uvs[i][j][1])
bm.to_mesh(me)
me.update()
bm.free

Note: node['UV'] is a list of uv name and uv index, uv_dic is a dictionary of the uv values.

**System Information** Operating system: macOS-13.3.1-arm64-arm-64bit 64 Bits Graphics card: Apple M1 Apple 4.1 Metal - 83.1 **Blender Version** Broken: version: 3.5.0, branch: blender-v3.5-release, commit date: 2023-03-29 02:56, hash: 1be25cfff18b Worked: (newest version of Blender that worked as expected) **Short description of error** The first uv layer will be overwritten by the second uv layer **Exact steps for others to reproduce the error** This issue only appears in Blender 3.5, Blender 2.93/3.3/3.4/3.6 alpha have no issues. If I import two uv layers via Python script, the first uv layer will be overwritten by the second uv layer, while the second uv layer has no data at all; if I only import the first uv layer, the first uv layer will be correct, so I can confirm that the first uv layer is overwritten by the second uv layer. Here is my code: bm = bmesh.new() bm.from_mesh(me) for uv in node['UV']: uv_name = uv[0] uv_index = uv[1] uvs = uv_dic[uv_index] uv_layer = bm.loops.layers.uv.new(uv_name) bm.faces.layers.face_map.verify() for (i, f) in enumerate(bm.faces): for (j, l) in enumerate(f.loops): luv = l[uv_layer] luv.uv = (uvs[i][j][0], uvs[i][j][1]) bm.to_mesh(me) me.update() bm.free Note: node['UV'] is a list of uv name and uv index, uv_dic is a dictionary of the uv values.

testing.fbx

2.7 MiB

Mingfen Wang added the

labels 2023-04-25 04:02:35 +02:00

YimingWu commented

2023-05-12 07:56:40 +02:00

Probably related to:

blender/blender#107500

blender/blender#107491

Probably related to: https://projects.blender.org/blender/blender/issues/107500 https://projects.blender.org/blender/blender/issues/107491

Germano Cavalcante commented

2023-05-13 00:19:13 +02:00

Thanks for taking time making the report, but please provide a working script so we can properly replicate the issue.
Also note that you reported this issue in the blender-addons repository but no addons were reported.

Thanks for taking time making the report, but please provide a working script so we can properly replicate the issue. Also note that you reported this issue in the [blender-addons](https://projects.blender.org/blender/blender-addons) repository but no addons were reported.

Germano Cavalcante added

Status

Needs Information from User

and removed

Status

Needs Triage

labels 2023-05-13 00:19:21 +02:00

Mingfen Wang commented

2023-05-13 05:14:09 +02:00

Sorry I don't have a working script at present, for my add-on is so complicated that I can't make a simple testing script from the source code, I guess that the issue may be caused by this line:

luv = l[uv_layer]

Where luv should be a pointer of the uv layer by uv name, but luv was always wrongly mapped to the first uv layer in Blender 3.5, in other Blender versions(3.3/3.4/3.6 alpha) the mappings are correct.

Sorry I don't have a working script at present, for my add-on is so complicated that I can't make a simple testing script from the source code, I guess that the issue may be caused by this line: luv = l[uv_layer] Where luv should be a pointer of the uv layer by uv name, but luv was always wrongly mapped to the first uv layer in Blender 3.5, in other Blender versions(3.3/3.4/3.6 alpha) the mappings are correct.

Germano Cavalcante commented

2023-05-22 16:29:46 +02:00

OK. I took some time to complete the code myself. But I couldn't replicate the issue described. It worked normally as expected. So I'm going to assume that the problem is somewhere else, probably not a bug in Blender. So closing since this report also has no activity for more than a week.

import bpy
import bmesh
import numpy as np

node = {'UV':[("my_uv1", 0), ("my_uv2", 1)]}
me = bpy.context.object.data

uv1 = np.empty((len(me.polygons) * 4 * 2), dtype=np.float32)
me.uv_layers['UVMap'].uv.foreach_get('vector', uv1)
uv1.shape = (len(me.polygons), 4, 2)
uv2 = uv1.copy()
uv2 *= 2

uv_dic = (uv1, uv2)

bm = bmesh.new()
bm.from_mesh(me)
for uv in node['UV']:
    uv_name = uv[0]
    uv_index = uv[1]
    uvs = uv_dic[uv_index]
    uv_layer = bm.loops.layers.uv.new(uv_name)
    bm.faces.layers.face_map.verify()
    for (i, f) in enumerate(bm.faces):
        for (j, l) in enumerate(f.loops):
            luv = l[uv_layer]
            luv.uv = (uvs[i][j][0], uvs[i][j][1])

bm.to_mesh(me)
me.update()
bm.free

OK. I took some time to complete the code myself. But I couldn't replicate the issue described. It worked normally as expected. So I'm going to assume that the problem is somewhere else, probably not a bug in Blender. So closing since this report also has no activity for more than a week. ```py import bpy import bmesh import numpy as np node = {'UV':[("my_uv1", 0), ("my_uv2", 1)]} me = bpy.context.object.data uv1 = np.empty((len(me.polygons) * 4 * 2), dtype=np.float32) me.uv_layers['UVMap'].uv.foreach_get('vector', uv1) uv1.shape = (len(me.polygons), 4, 2) uv2 = uv1.copy() uv2 *= 2 uv_dic = (uv1, uv2) bm = bmesh.new() bm.from_mesh(me) for uv in node['UV']: uv_name = uv[0] uv_index = uv[1] uvs = uv_dic[uv_index] uv_layer = bm.loops.layers.uv.new(uv_name) bm.faces.layers.face_map.verify() for (i, f) in enumerate(bm.faces): for (j, l) in enumerate(f.loops): luv = l[uv_layer] luv.uv = (uvs[i][j][0], uvs[i][j][1]) bm.to_mesh(me) me.update() bm.free ```

Germano Cavalcante closed this issue

2023-05-22 16:29:47 +02:00

Blender Bot added

Status

Archived

and removed

Status

Needs Information from User

labels 2023-05-22 16:29:48 +02:00

Mingfen Wang commented

2023-05-25 01:26:07 +02:00

I have just tested the code in Blender 3.5.0, the bug is still there, but after I upgraded to Blender 3.5.1, the bug has gone, so I confirmed that the bug has been fixed in Blender 3.5.1, it works correctly now:)

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