FBX exporter writes malformed 'Current' section #41307

New Issue

Raul Aguaviva · 2014-08-04T01:19:47+02:00

Raul Aguaviva commented

2014-08-04 01:19:47 +02:00

System Information
Win7, AMD r9 290

Blender Version
just tried 2.71 hash 9337574

Short description of error
FBX exporter generates a malformed 'Current' section

Exact steps for others to reproduce the error
Created a simple scene, just suzzane with a texture. suzzane.blend
Exported and FBX with the default options. suzzane2.fbx
When tried to load the FBX with my FBX loader I realized that the string length of the property 'Current' is zero, see hexdata below .
You can also see that from then on all the data is garbage and then the file finishes a few bytes later (128 bytes or so).

According to the ascii export, the string length should be "Default Take" and the string length should be 12. Also all the 'Take' nodes are missing that should come after this node are missing.

**System Information** Win7, AMD r9 290 **Blender Version** just tried 2.71 hash 9337574 **Short description of error** FBX exporter generates a malformed 'Current' section **Exact steps for others to reproduce the error** Created a simple scene, just suzzane with a texture. [suzzane.blend](https://archive.blender.org/developer/F101418/suzzane.blend) Exported and FBX with the default options. [suzzane2.fbx](https://archive.blender.org/developer/F101420/suzzane2.fbx) When tried to load the FBX with my FBX loader I realized that the string length of the property 'Current' is zero, see hexdata below ![undefined](https://archive.blender.org/developer/F101421/undefined). You can also see that from then on all the data is garbage and then the file finishes a few bytes later (128 bytes or so). According to the ascii export, the string length should be "Default Take" and the string length should be 12. Also all the 'Take' nodes are missing that should come after this node are missing.

Raul Aguaviva commented

2014-08-04 01:19:47 +02:00

Changed status to: 'Open'

Raul Aguaviva commented

2014-08-04 01:19:47 +02:00

Added subscriber: @xchip

Bastien Montagne self-assigned this 2014-08-04 10:56:08 +02:00

Bastien Montagne commented

2014-08-04 10:56:08 +02:00

I’m not en axpert in FBX format (who is? there are no official specs afaik), but from what I’ve seen so far, in recent versions (7.3, 7.4), takes are completely deprecated, animations being handled by AnimStack, so yes, 7.4 bin exporter does not really care about Takes.

I wonder why 'Current' could not be zero lenght len? Anyway, adding "Default Take" in here instead is easy, just wondering why it would be needed… FBX…

I’m not en axpert in FBX format (who is? there are no official specs afaik), but from what I’ve seen so far, in recent versions (7.3, 7.4), takes are completely deprecated, animations being handled by AnimStack, so yes, 7.4 bin exporter does not really care about Takes. I wonder why 'Current' could not be zero lenght len? Anyway, adding "Default Take" in here instead is easy, just wondering why it would be needed… FBX…

Raul Aguaviva commented

2014-08-04 11:46:52 +02:00

Hi Mont29,

You are right, the string could be zero. In fact my loader just parses everything fine but stops right before the "ú¼« ÐÈÔf±vûƒ÷&~ " Any idea what that chunk is?

Hi Mont29, You are right, the string could be zero. In fact my loader just parses everything fine but stops right before the "ú¼« ÐÈÔf±vûƒ÷&~ " Any idea what that chunk is?

Bastien Montagne commented

2014-08-04 12:12:33 +02:00

Here is the JSon-converted (exact) content of the end of the data-part of your FBX file:

  ["Connections", [], "", [
      ["C", ["OO", 93497060, 0], "SLL", []],
      ["C", ["OO", 592341770, 0], "SLL", []],
      ["C", ["OO", 850149994, 0], "SLL", []],
      ["C", ["OO", 999062126, 0], "SLL", []],
      ["C", ["OO", 923864498, 0], "SLL", []],
      ["C", ["OO", 234064505, 93497060], "SLL", []],
      ["C", ["OO", 704066782, 592341770], "SLL", []],
      ["C", ["OO", 601346663, 850149994], "SLL", []],
      ["C", ["OO", 305518367, 999062126], "SLL", []],
      ["C", ["OO", 658446846, 923864498], "SLL", []],
      ["C", ["OO", 764020131, 850149994], "SLL", []],
      ["C", ["OP", 797983990, 764020131, "DiffuseColor"], "SLLS", []],
      ["C", ["OO", 592489931, 797983990], "SLL", []]]],
  ["Takes", [], "", [
      ["Current", [""], "S", []]]]]

After that (see encode_bin.py file of the addon), we write a foot ID (fa bc ab 09 d0 c8 d4 66 b1 76 fb 83 1c f7 26 7e), some padding, the version of the file, and some final magic content…

In other words, once you hit that binary chain above, data content is finished.

Here is the JSon-converted (exact) content of the end of the data-part of your FBX file: ``` ["Connections", [], "", [ ["C", ["OO", 93497060, 0], "SLL", []], ["C", ["OO", 592341770, 0], "SLL", []], ["C", ["OO", 850149994, 0], "SLL", []], ["C", ["OO", 999062126, 0], "SLL", []], ["C", ["OO", 923864498, 0], "SLL", []], ["C", ["OO", 234064505, 93497060], "SLL", []], ["C", ["OO", 704066782, 592341770], "SLL", []], ["C", ["OO", 601346663, 850149994], "SLL", []], ["C", ["OO", 305518367, 999062126], "SLL", []], ["C", ["OO", 658446846, 923864498], "SLL", []], ["C", ["OO", 764020131, 850149994], "SLL", []], ["C", ["OP", 797983990, 764020131, "DiffuseColor"], "SLLS", []], ["C", ["OO", 592489931, 797983990], "SLL", []]]], ["Takes", [], "", [ ["Current", [""], "S", []]]]] ``` After that (see encode_bin.py file of the addon), we write a foot ID (`fa bc ab 09 d0 c8 d4 66 b1 76 fb 83 1c f7 26 7e`), some padding, the version of the file, and some final magic content… In other words, once you hit that binary chain above, data content is finished.

Raul Aguaviva commented

2014-08-04 12:30:01 +02:00

Excellent, I am getting the same output, all is fine then :) The no string and the foot ID confused me and made me think it was garbage.

Where are you getting those 'SLL'? All I am getting is this:

Connections (0)
    C (3) OO 93497060 0
    C (3) OO 592341770 0
    C (3) OO 850149994 0
    C (3) OO 999062126 0
    C (3) OO 923864498 0
    C (3) OO 234064505 93497060
    C (3) OO 704066782 592341770
    C (3) OO 601346663 850149994
    C (3) OO 305518367 999062126
    C (3) OO 658446846 923864498
    C (3) OO 764020131 850149994
    C (4) OP 797983990 764020131 DiffuseColor
    C (3) OO 592489931 797983990
Takes (0)
    Current (1)

And I dont see those strings in the hex dump.

Cheers!

Excellent, I am getting the same output, all is fine then :) The no string and the foot ID confused me and made me think it was garbage. Where are you getting those 'SLL'? All I am getting is this: ``` Connections (0) C (3) OO 93497060 0 C (3) OO 592341770 0 C (3) OO 850149994 0 C (3) OO 999062126 0 C (3) OO 923864498 0 C (3) OO 234064505 93497060 C (3) OO 704066782 592341770 C (3) OO 601346663 850149994 C (3) OO 305518367 999062126 C (3) OO 658446846 923864498 C (3) OO 764020131 850149994 C (4) OP 797983990 764020131 DiffuseColor C (3) OO 592489931 797983990 Takes (0) Current (1) ``` And I dont see those strings in the hex dump. Cheers!

Bastien Montagne commented

2014-08-04 12:36:27 +02:00

We have a tool, fbx2json.py (I just pushed it into official addon repo), which converts bin FBX into a nice readable (and parsable!) JSon format (SLL are the type of the three values, string, long, long - FBX conventions ;) ).

See also (in case you do not know them already):

Binary format: http://code.blender.org/index.php/2013/08/fbx-binary-file-format-specification
Data layout (very incomplete and rather fuzzy in some areas :/ ): http://wiki.blender.org/index.php/User:Mont29/Foundation/FBX_File_Structure

We have a tool, fbx2json.py (I just pushed it into official addon repo), which converts bin FBX into a nice readable (and parsable!) JSon format (SLL are the type of the three values, string, long, long - FBX conventions ;) ). See also (in case you do not know them already): * Binary format: http://code.blender.org/index.php/2013/08/fbx-binary-file-format-specification * Data layout (very incomplete and rather fuzzy in some areas :/ ): http://wiki.blender.org/index.php/User:Mont29/Foundation/FBX_File_Structure

Bastien Montagne commented

2014-08-04 13:50:59 +02:00

Changed status from 'Open' to: 'Archived'

Bastien Montagne closed this issue

2014-08-04 13:50:59 +02:00

Bastien Montagne commented

2014-08-04 13:50:59 +02:00

Thinsk we can close that, btw, since this is not a bug. :)

Raul Aguaviva commented

2014-08-05 11:09:26 +02:00

thanks for your help! I had the first link but not the second one, very useful :)

Cheers!

thanks for your help! I had the first link but not the second one, very useful :) Cheers!

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

FBX exporter writes malformed 'Current' section #41307