FBXDocument Reader and Writer are incompatible WRT byte data about fbxwriter

[kianzarrin]

btw does your library capable of producing binary fbx directly from unity without the need to use UnityFBXExporter.FBXExporter.MeshToString?

[kianzarrin]

I also had to add a special case here to read byte

FbxWriter/Fbx/FbxBinary.cs

Line 103 in 53d9479

if (prop is int || prop is long)

that solved all the exceptions.

but I still cannot open the generated file even though I can open the original ascii
fbx files.zip

can you please tell me what I should do?
.

[kianzarrin]

I wrote this code to understand where is the problem:

            var doc = FbxIO.ReadAscii(dir + file1);
            string fileA = "testA_" + file1;
            FbxIO.WriteAscii(doc, dir + fileA);

            doc = FbxIO.ReadAscii(dir + fileA);
            string fileB = "testB_" + file1;
            FbxIO.WriteBinary(doc, dir + fileB); // i can't open this

            doc = FbxIO.ReadBinary(dir + fileB);
            FbxIO.WriteAscii(doc, dir + "testC_" + file1); // i can open this

the code does not throw an exception (after the fixes I made to FbxWriter).
I tried view the files using FBX viewer https://overbits.herokuapp.com/fbxgltf/
using the FBX viewer above I can open the ascii outputs but not the binary outputs.
if I read the binary output and write it again as ascii then I can view it again.

blender gave me the following error when I opened the binary fbx file

[kianzarrin]

I converted the ascii fbx to binary fbx with this tool and it worked:
https://github.com/BobbyAnguelov/FbxFormatConverter
unfortunately, it's in c. I need in c#

I ran this test to gain more debugging info:

            string file1 = "RoadMediumNode.binary.fbx"; // can open this

            var doc = FbxIO.ReadBinary(dir + file1); 
            string fileA = "testA_" + file1;
            FbxIO.WriteBinary(doc, dir + fileA); // can open this
            
            doc = FbxIO.ReadBinary(dir + file1);
            string fileB = "testB_" + file1;
            FbxIO.WriteAscii(doc, dir + fileB); // can open this

            doc = FbxIO.ReadAscii(dir + fileB);
            FbxIO.WriteBinary(doc, dir + "testC_" + file1);  // can' open this

read working binary fbx -> write as binary fbx -> works
read working ascii fbx created FbxFormatConverter -> write as binary fbx -> does not work.

conclusion:
I am suspecting that the bug is an incompatibility between ascii reader and binary writer.
Note that I ran these tests after applying the fixes I suggested in the comments bellow