One nice thing about free assets is that you would be able to modify and remix them. So you could take some existing model of a car, change the dimensions a bit, change the shading, exaggerate some of its features and get a cartoon car that looks completely different.
Another thing is that you would not have to reinvent the wheel each time. Sure, you expect the important bits of each game to be unique. But do you really care that the wooden crates or doors from one game are reused in another? Being able to take an existing model of something unimportant and tweak it to match your atmosphere would save a lot of pointless work.
Just having access to such a library would not stop a good game development team for making a creative, distinctive game. It would just save them from having to make a whole bunch of boring models of limited utility. They would still make all the core models--characters, exotic settings and so on--for each particular game.
Besides, I think game studios already share assets between similar games in their own lineup. This would just make the sharing global, giving everybody access to more material to start from.
My main objection comes from the fact that I do both development and design, and I've seen a lot of developers act like art can be reused just the same as code, with no ill effects. But humans are excellent pattern matchers, and we do pick up on these things.
Personally I mostly enjoy games for their story and atmosphere, and the few times I've recognized a reused asset (e.g. a sound effect) it's been really distracting. It's like the Wilhelm Scream in movies... once you know about it, you can never stop noticing it.
A better idea would be to make an open library for procedural generation of assets, so that you can make infinite variations of every item, and tweaking is easy. We already have e.g. SpeedTree, but these things are so valuable they always end up being commercial rather than free.
> the few times I've recognized a reused asset (e.g.
> a sound effect)
The "pig farm" sound effect from WarCraft II... I've heard that one a lot. From tv shows to films to other games. The only one I can pull off the top of my head of Ghost in the Shell: Stand-Alone Complex Season 1.
But mods generally fall into two categories... those that take place within the existing game's world, and total conversions. In the case of total conversions, what's being reused is typically the engine, not the assets, and in the other case, you're deliberately trying to fit in.
