Homeworld used Lightwave (I think) as its 3D modelling tool/format and it is not free.
Yes, but free, shareware, and inexpensive 3rd party tools could be used, and were used, to create content for Homeworld 1 mods.
When we open up Homeworld to better support mods we should try and ensure that there are no financial restrictions on the ability to create new content.
Like Homeworld 2
We should also try and support an open/industry standard format for 3D models.
It's not so much what the game designers used... it's more of a question of the model format supporting conversions to/from free or inexpensive third party software.
Unfortunately the crux in modding HW was the 3D Exploration
3D model conversion app, which could read and write to the HW peo format and thus convert it to any number
of formats that various 3D modelling programs could access. Unfortunately 3DX is no longer a "free or inexpensive" option.
I have to admit to absolutely no knowledge in this domain though. Can anyone recommend:
1) an open/industry standard 3D format we could use that has...
That would involve a serious rewrite of the HW core, but is technically possible.
2) free/cheap 3D modelling editors available on all platforms* which support it? (If so, what are they?)
Again: there is no need for everyone to use a common editor, and indeed such would restrict modders very uneccessarily.
What is needed is a model format that is easily converted to and from.