OBJ exporter: need option Keep Vertex Order #116519

New Issue

keaukraine · 2023-12-24T18:55:38+01:00

keaukraine commented

2023-12-24 18:55:38 +01:00

System Information
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3060 Laptop GPU/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 546.17

Blender Version
version: 3.4.1, branch: blender-v3.4-release, commit date: 2022-12-19 17:00, hash: rB55485cb379f7

Short description of error
New OBJ exporter doesn't have a "Keep Vertex Order" option.
Legacy OBJ exporter doesn't have this issue.

Exact steps for others to reproduce the error

Export some model with animations.2
Different frames have different vertex order.
If the same is done with legacy OBJ exporter, the "Keep Vertex Order" can be enabled to keep vertex order.

**System Information** Operating system: Windows-10-10.0.19045-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 3060 Laptop GPU/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 546.17 **Blender Version** version: 3.4.1, branch: blender-v3.4-release, commit date: 2022-12-19 17:00, hash: `rB55485cb379f7` **Short description of error** New OBJ exporter doesn't have a "Keep Vertex Order" option. Legacy OBJ exporter doesn't have this issue. **Exact steps for others to reproduce the error** 1. Export some model with animations.2 2. Different frames have different vertex order. If the same is done with legacy OBJ exporter, the "Keep Vertex Order" can be enabled to keep vertex order.

keaukraine added the

labels 2023-12-24 18:55:39 +01:00

Aras Pranckevicius changed title from ~~New Wavefront OBJ exporter doesn't support Keep Vertex Order~~ to OBJ exporter: need option Keep Vertex Order

2023-12-25 11:21:51 +01:00

Aras Pranckevicius commented

2023-12-25 11:22:23 +01:00

@keaukraine hmm I thought that the new exporter always keeps the vertex order. Can you attach some file that reproduces the issue?

@keaukraine hmm I thought that the new exporter _always_ keeps the vertex order. Can you attach some file that reproduces the issue?

Aras Pranckevicius self-assigned this 2023-12-25 11:22:36 +01:00

Aras Pranckevicius added

Status

Needs Information from User

and removed

Status

Needs Triage

labels 2023-12-25 11:23:32 +01:00

Aras Pranckevicius added this to the Pipeline, Assets & IO project 2023-12-25 11:23:41 +01:00

keaukraine commented

2023-12-25 15:49:54 +01:00

Here is a test file.
This is a free asset from Quaternius Animals Pack.
I've applied some modifiers (triangulate + decimate) and exported "Idle1" animation.
This is exported just fine with the legacy exporter but is broken with the new one.

Then compare result OBJ files. In most of them order is kept intact but for example files 11 and 112 will have different faces order. This is not the case with the legacy exporter.

Also (this is reported in another ticket) you can see that animation file names are strange - starting from 11 and ending with 135 which doesn't corellate with frame numbers, and are not padded with zeros so are not alphabetically ordered.

Here is a test file. This is a free asset from Quaternius Animals Pack. I've applied some modifiers (triangulate + decimate) and exported "Idle1" animation. This is exported just fine with the legacy exporter but is broken with the new one. Then compare result OBJ files. In most of them order is kept intact but for example files 11 and 112 will have different faces order. This is not the case with the legacy exporter. Also (this is reported in another ticket) you can see that animation file names are strange - starting from 11 and ending with 135 which doesn't corellate with frame numbers, and are not padded with zeros so are not alphabetically ordered.

Alpaca-idle1.blend

2.5 MiB

Aras Pranckevicius commented

2023-12-25 21:09:46 +01:00

@keaukraine I'm not sure where exactly I should be looking at in this repro file. If I export it to OBJ with animation on, then I get the same amount of vertices, normals and faces in all cases. And the faces are slightly different (i.e. different in which vertex normal they refer to), in all the scenarios: old OBJ exporter, old OBJ exporter with Keep Vertex Order option, and new OBJ exporter. So I'm not sure what exactly has changed (from what I can tell, "they are slightly different in all these cases"), or I need more details to see what exactly is wrong.

Aras Pranckevicius commented

2023-12-25 21:11:34 +01:00

animation file names are strange - starting from 11 and ending with 135 which doesn't corellate with frame numbers

That is by design I think -- the filename itself ends with "idle1", and so when it appends the frame numbers to that it ends up with "11" through to "135". Anyway I'm fixing the leading zeroes issue.

> animation file names are strange - starting from 11 and ending with 135 which doesn't corellate with frame numbers That is by design I think -- the filename itself ends with "idle1", and so when it appends the frame numbers to that it ends up with "11" through to "135". Anyway I'm fixing the leading zeroes issue.

keaukraine commented

2023-12-26 00:12:30 +01:00

Oh, file names are okay except for missing padding with zeroes. Indeed I missed that Idle1 part.
Will take a closer look at exported files but my automated integrity check in bash scripts detected these differences only with files exported with the new exporter. Legacy OBJs have imported just fine.

Oh, file names are okay except for missing padding with zeroes. Indeed I missed that Idle1 part. Will take a closer look at exported files but my automated integrity check in bash scripts detected these differences only with files exported with the new exporter. Legacy OBJs have imported just fine.

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OBJ exporter: need option Keep Vertex Order #116519