Repeated file block addresses in files saved with 3.5.1 #108150

New Issue

arturoc · 2023-05-22T17:14:34+02:00

arturoc commented

2023-05-22 17:14:34 +02:00

System Information
Operating system: Linux-6.2.0-1003-lowlatency-x86_64-with-glibc2.37 64 Bits
Graphics card: NVIDIA GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 525.105.17

Blender Version
Broken: version: 3.5.1, branch: blender-v3.5-release, commit date: 2023-04-24 18:11, hash: e1ccd9d4a1d3
Worked: version 3.4.1

Just for reference: the following commits seem to have introduced this :

Short description of error
While trying to read the content of a blender file using a custom tool following the format description in "The mystery of the blend" several "DATA" file blocks have the same old address when the file is saved with blender 3.5.0, 3.5.1 or the current beta for 3.6.0 (3.6.0-beta+v36.52f991b1a9b3). This doesn't happen with files saved with versions up until 3.4.1 although those also have a DrawDataList in the "REND" block and a FileGlobal in the "GLOB" block with the same old address.

As far as I understand there should never be two or more blocks with the same address. Also the blocks have different sizes and in some cases even different types, usually with the data content of meshes, ie: vertices, loops, uv loops...

What seems to be happening is that the vertex data in the original mesh and the duplicated one are saved with the same addresses.

Exact steps for others to reproduce the error

Not sure if there's other ways to replicate the error but duplicating a mesh and then editing the vertices on the copy seems to create a file with this problem.

Adding the following lines to the BlendFileReader.py in doc/blender_file_format shows the file blocks with duplicated addresses:

def main():
    handle = openBlendFile(PATH_TO_FILE_TO_PARSE)
    blend = BlendFile(handle)
    blockaddrs = set()
    for block in blend.Blocks:
        if block.Header.OldAddress in blockaddrs:
            print("Duplicated", block.Header.OldAddress)
        else:
            blockaddrs.add(block.Header.OldAddress)

if __name__ == '__main__':
    main()

Attached are two files demonstrating the problem, the one saved with blender 3.3.6 doesn't have data blocks with the same address. The one saved with 3.5.1 has two vertices and uv loop data blocks duplicated. The file was created in 3.5.1 by duplicating a sphere and modifying it's vertices and faces. The version saved with 3.3.6 is the same file just opened in 3.3.6 and saving it with a different name. as _336.

**System Information** Operating system: Linux-6.2.0-1003-lowlatency-x86_64-with-glibc2.37 64 Bits Graphics card: NVIDIA GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 525.105.17 **Blender Version** Broken: version: 3.5.1, branch: blender-v3.5-release, commit date: 2023-04-24 18:11, hash: `e1ccd9d4a1d3` Worked: version 3.4.1 Just for reference: the following commits seem to have introduced this : - 1af62cb3bf46f0cd328ab0840a1363eca938c628 - 6c774feba2c9a1eb5834646f597a0f2c63177914 **Short description of error** While trying to read the content of a blender file using a custom tool following the format description in "The mystery of the blend" several "DATA" file blocks have the same old address when the file is saved with blender 3.5.0, 3.5.1 or the current beta for 3.6.0 (3.6.0-beta+v36.52f991b1a9b3). This doesn't happen with files saved with versions up until 3.4.1 although those also have a DrawDataList in the "REND" block and a FileGlobal in the "GLOB" block with the same old address. As far as I understand there should never be two or more blocks with the same address. Also the blocks have different sizes and in some cases even different types, usually with the data content of meshes, ie: vertices, loops, uv loops... What seems to be happening is that the vertex data in the original mesh and the duplicated one are saved with the same addresses. **Exact steps for others to reproduce the error** Not sure if there's other ways to replicate the error but duplicating a mesh and then editing the vertices on the copy seems to create a file with this problem. Adding the following lines to the `BlendFileReader.py` in `doc/blender_file_format` shows the file blocks with duplicated addresses: ```Py def main(): handle = openBlendFile(PATH_TO_FILE_TO_PARSE) blend = BlendFile(handle) blockaddrs = set() for block in blend.Blocks: if block.Header.OldAddress in blockaddrs: print("Duplicated", block.Header.OldAddress) else: blockaddrs.add(block.Header.OldAddress) if __name__ == '__main__': main() ``` Attached are two files demonstrating the problem, the one saved with blender 3.3.6 doesn't have data blocks with the same address. The one saved with 3.5.1 has two vertices and uv loop data blocks duplicated. The file was created in 3.5.1 by duplicating a sphere and modifying it's vertices and faces. The version saved with 3.3.6 is the same file just opened in 3.3.6 and saving it with a different name. as _336.

BlendFileReader.py

13 KiB

test_cube_sphere_351.blend

872 KiB

test_cube_sphere_336.blend

835 KiB

arturoc added the