285 Photo model.. exported obj file is 2GB; how to reduce file size?

[ThursdayJuly23rd]

My exported obj file was 2GB... too big to upload to sketchfab ... just wondering if there is some documentation on how to reduce file size of the exported obj files. Thank you!

[Andrea Alessi]

Hi,

you can use the decimation filter or select a target polycount when generating your mesh, or eventually export your mesh in any third party software (e.g. blender), do your editing, then reimport it in zephyr for texturing.

[ThursdayJuly23rd]

Thank you; I'll try that.

[DanielMuirhead]

I tend to upload directly from 3DF Zephyr (which, in textured mesh dialogue, for upload to Sketchfab has option to automatically down-size model to fit within a specified Sketchfab upload limit, i.e. 50mb Free/200mb Pro/500mb Premium).

Back in the good ol' days when I exported the model from the photogrammetry software then manually uploaded that export, I compressed it with 7zip into a ZIP to reduce file size. OBJs were the preferable file format to do this with (e.g. compared to FBX), with OBJ (if I remember rightly) the file zipped down to around 35% of its original size. So e.g. if working with Sketchfab limit of 50mb, you want OBJ of max size 150mb. Another tip with Sketchfab is that textures can be uploaded after the fact, and do not count towards max file size. So e.g. if uploading a textured model as a ZIP (OBJ+MTL+JPG), upload the JPG texture as a 1k, then supplant that texture with an 8k.

All that said, unless your model is something ridiculously large or complex, it should be possible to reduce its file size in 3DF to around 100k vertices/200k faces (Mesh Filter> Decimation, applied to the Mesh prior to the texturing), texture it with an 8k texture, and have it fit comfortably within the 50mb upload limit. If necessary (and if you have access to at least Zephyr Lite or up) you can 'bake' some of the mesh geometry into a normal map. I discuss and demonstrate Normal Maps in one of my blog posts here (if 3Dflow do not mind me sharing my own website): https://danielmuirhead3d.art/2020/08...-to-sketchfab/ - under the heading 'Demonstration of Decimation and Normal Maps'.