J3D File Format

[Jeff-Groves]

Here's the start of the 010 template for j3d files.
http://www.mediafire.com/file/f93une...bz/j3d.7z/file

This template will take you to the start of the faces.
It reads the file just as is!

[FPSchazly]

Cool stuff. Keep it up!

[Jeff-Groves]

Thank You!

I plan to do lots more in the long run.
A stand alone exporter is pretty simple to do but I'd like to create a new program to create new j3d files.

[Polak2]

Very interesting!

It could be perhaps handy for you to know that 3DObject converter handles reading j3d and displaying it including UWV coordinates materials etc. for nice and easy conversion to various editable formats.

What is still problematic is :
a. plugin to go back from any editable format back to j3d is only available to 3dsMax3.1 which unfortunately is not so popular or easily available any longer
b. what is even worse in that plugin there is a limitation of vertices of 32768 which is rather annoying and prevents most of the more complex models from exporting.

Do you think such a limitation could be removed or better yet new plugin for newer 3dsMax versions could be made ?

[Jeff-Groves]

I have 3DConverter. A legal lifetime version.
I also have 3D Studio 3.1 and the j3d exporter.

Now is the exporter the limiting factor on verts? Or the Game engine?

I can Hex edit a file to run way over that but would need to test it in Game.
I bought DW from Amazon but it won't run.

[Polak2]

Now is the exporter the limiting factor on verts? Or the Game engine?

Exporter, 99.9% sure. RA modders having j3d models which are way beyond this limit of 32768 . If you can hexedit this barier I can gladly test it.

[Jeff-Groves]

Kara2 seems to be the largest 3D file and does not exceed 32181 polys
nor more then 29009 verts.
Of which only 22750 verts are shown in 3D object converter.

Interesting to note you need to jump down the file to decode the verts.

The 212_esm. j3d file is even more interesting.

[Battlewagon3]

Originally Posted by Jeff-Groves

Here's the start of the 010 template for j3d files.
http://www.mediafire.com/file/f93une...bz/j3d.7z/file

This template will take you to the start of the faces.
It reads the file just as is!

I'm replying to thank you now before I forget. It could be a few months before I chase this down properly. I've been very busy learning how to code (really) for my studies, so games modding has taken a backseat. As you'll see from my other posts, though, every few months I come back with questions and try a few more things. I'm not ignoring you!

[HoneyFox]

I took several hours researching the j3d file format, and here is what I've found (see attachment).

It's written in C++ style, although C++ doesn't support declaring array of uncertain length, but... you get what I mean.

PS1: There are still some unknown items, but they seem to be constant during my research over dozens of .j3d files.
PS2: It's still far from having a new exporter. Major challenge is to find a suitable input model format and write a parser for it, especially when dealing with models containing hierarchy.
PS3: Actually I'm not sure if that use_tex and render_order is correct or not, I found no value to store the material index of model, but it doesn't seem to match if we assume it is.

[Polak2]

Interesting work and progress.

Are you trying to make a new exporter plugin like DWj3dexporter2004 which has some limitations of polygons being able to export as well as being compatible with a very old version of 3dsMax?
I assume that you are aware that j3d is part of the 3D ObjectConverter and can load models but not save them back to j3d.

Perhaps there is something we can help with?

[Polak2]

Perhaps of some help would be a structure of DW database where some of the j3d elements are mentioned.

I think it is included in DWEdit1_7_4_1 which was in DW Download section on this forum.

[HoneyFox]

Originally Posted by Polak2

Perhaps of some help would be a structure of DW database where some of the j3d elements are mentioned.

I think it is included in DWEdit1_7_4_1 which was in DW Download section on this forum.

Oh, my aim is to have a tool for exporting j3d models for JFC. I don't know if this file format has changed or not when it comes to DW.

Anyway this is the current workflow: modeling in Blender 3.x -> Blender 3.x Wavefront obj exporter (I modified the wavefront obj exporter so that the hierarchy/offset info can be exported as well) -> Wavefront obj file -> My exporter -> J3D file -> cmpUtils.exe -> GraphicsDB.

Too bad that subsim doesn't allow me to upload .zip file attachment...

[Polak2]

Originally Posted by HoneyFox

Oh, my aim is to have a tool for exporting j3d models for JFC. I don't know if this file format has changed or not when it comes to DW.

Word of caution: as DW j3d plugin had a limit of 32K polys on the models it is very probable that JFC (being the earliest) would have some hard limits on 3D models as well. It was dictated by the HW in those days.