So you wanted to make a 3D skybox for your Portal 2 map, browsed for skybox models but didn't find any and now you are disppointed.

Don't be!

This zip-file contains some skybox models that could get you started. Copy the contained folders into the model folder.

You can create your own skybox models from the existing models in the game without any modelling experience when you follow these tutorials:

1. Decompile the model you want, as explained by Skotty here.

2. Rescale the model as explained in this tutorial on interlopers.net

3. Compile the new model following Josepezdj's tutorial here.

If you do so, let me know via PM or upload the file attached to a reply in this thread and I'll add your models to the zip-file.

File Name: skybox_models.rar
File Size: 2.42?MiB
Click here to download The 3D skybox models thread

So far, this file contains:

Old Aperture:

- Geodomes with different sizes and quality for old Aperture maps, made by Skotty
(produce yellow errors when compiling, but work absolutely fine)



Walkways:

- the 128 and 512 units long walkways
- walkway corner
- the 64 units long destroyed walkway
- the 256 units long hanging stairs

by josepezdj and me



Vactubes:

- corkscrew piece
- crossroads
- skybox_1024_pipe_2, a long straight vactube, made by LPFreaky90



Arms:

- arm_ext_halfres_rows_4x4


Examples how these could be pieced together:

Right, fixed.

To anyone who downloaded and doesn't know why the models are so tiny (like me) check this out.
https://developer.valvesoftware.com/wiki/3d_skybox