3ds max fbx export issue


(Ripvannik) #1

Hi.
I'm using 3ds max to optimize a mesh created from a scan but have encountered a problem.

The mesh is 250mb in the meshing application, (sequoia) which i then import into max using a script.

I then clean up and optimize the mesh in max by 50 percent, expecting a smaller fbx once I export it.

The problem is that the fbx jumps from 250mb to 800mb meaning it's incompatible with sketchfabs uploader.

Are there elements I can delete from the max scene prior to exporting ? I've tried welding all the segments together too but not having any luck.

Any advice greatly appreciated.
Stephen.


#2

Hi Stephen,

A few ideas:

1) Are you exporting binary or ascii FBX? The binary version will be much smaller

2) Do you have large texture files that you can remove from the FBX (Embedded Media option in export settings)?

3) We support uploading compressed ZIP/RAR/7z archives, which can also save a lot of space.


(Ripvannik) #3

Thanks James.
I only have vertex colours baked into the mesh as opposed to any associated texture map.
i'll look into the binary export and get back to you.

Cheers.
Stephen.


(Ripvannik) #4

HI James.
I checked my settings and i was already on the binary mode. The ascii version produced a 3gb file !
Compressing using 7z resulted in a reduction from 800mb to 700mb Approx.

I had a look around the 3ds forums and theres a lot of posts about similar experiences. From what i can gather the fbx export contains a huge amount of data to enable third party software to read the geometry, whereas in max, the software does most of the work.

I'm going to try using the sketchfab max script to see if this helps, but it looks like i'll need to find another piece fof software that works with sketchfab, to tidy up the mesh after i've edited the point cloud and converted it in sequoia. Would you be interested in receiving a copy of the fbx to see if the browser could handle the geometry ?
I've uploaded less compressed verions previously, directly from sequoia, but the max version is definitely cleaner and less cluttered.

Kind Regards.
Stephen.


#5

Hi Stephen,

Yes, it could be useful to see the file if you can share it with me. How many vertices/faces are we talking about here?

James


(Ripvannik) #6


#7

Ok. It's very heavy but we should be able to handle a model of that size. Have you tried exporting OBJ? Not sure about the raw OBJ vs FBX size, but OBJ will compress very efficiently.


(Ripvannik) #8

Hi James. I'll look into obj and get back to you with both the fbx and obj files to see what you think.

Cheers.
S.


(Ripvannik) #9

HI James. I emailed and sent a link from wetransfer to the community@sketchfab.com address with the data.
Let me know when you receive it.

Cheers.
Stephen.


#10

Got it! I'll take a look as soon as I can.


(Ripvannik) #11

​Cheers James. The .obj was larger than the .fbx unfortunately unless i can figure something out in 3ds Max before i export it.

Sequoia can export .ply and .stl files directly or it has a script for max which is why i am using .fbx.

Can anyone recommend an alternative mesh editor compatible with sequoia (.ply / .stl) that would not load the file with so much data ?

I literally cut the mesh in half but its still reading 600mb of data in fbx format, while the mesh itself is under 200mb when originally exported from sequoia.

Thanks !
Stephen..


#12

I was able to get the OBJ down to 174 MB using heavy .7z compression. I even got it down to 136 MB by removing the vertex normal data and then compressing. However, this doesn't include your textures and .MTL file. If there is more than one material, you'll need to upload the OBJ + MTL, but the MTL should not be very big. You can either include the textures too, or add them later in 3D Settings if it makes the file too big.

I suspect that's why the FBX isn't being compressed very well if there are big textures embedded in the file.

Not sure if/when they will finish processing, but they should be ok. I added them to your account:

https://sketchfab.com/models/a3d642a0cf0442758da4819b2822ab1b
https://sketchfab.com/models/609f5d18370249708e0811b634ccfb12


(Ripvannik) #13

OK, thanks again.
I'm unclear on the difference beteen vertex colours baked into the mesh and texture maps added to the mesh seperately.

Sequoia offers bake vertex colours only option, which results in less memory being required during processing than when associating additional texture maps.

I wonder if theres a way to produce a texture map or .mtl file in 3ds and attach it seperatley in sketchfab ? Perhaps during the obj export ?

S.


#14

Vertex colors are attributes applied to the vertices.

http://wiki.polycount.com/wiki/Vertex_color
https://help.sketchfab.com/hc/en-us/articles/210765623-Vertex-Colors

Textures are images applied to the surface via UV mapping.

https://en.wikipedia.org/wiki/UV_mapping

Their relative performance and file sizes produced really depend on a lot of factors. You can read about Sketchfab performance here:

https://help.sketchfab.com/hc/en-us/articles/201766675-Viewer-Performance

Regarding texture creation in 3ds Max, our Exporter plugin actually has built-in options for baking materials/lighting into texture maps:

https://sketchfab.com/exporters/3dsmax


(Ripvannik) #15

Many Thanks James ! Plenty of info to get my head round there : )

I'll look into it and get back to you.

Best Regards.
Stephen.