What alternatives (free if possible) are there to Bryce?
The obvious leading contender is Vue. It’s extremely capable, but by the time you’ve got a version that matches Bryce’s features, you’ll have spent rather a lot of money. There are free ‘learning editions’, but they’re restricted.
Another possible is DAZ’s own Carrara, which - in addition to being a full-fledged modeling, animation and rendering program - has evolved into a surprisingly-good landscape modeler. Plus it handles DAZ/Poser content well. It’s a real Swiss Army knife of a program. Again, though, it’s not free. It also currently has some irritating show-stopper bugs on Mac at the moment: not enough to make it unusable, but enough to make you scream and punch the walls once in a while.
TerraRay is relatively inexpensive (and they have special offers from time to time) but, in my view, pretty limited. It’s quite slow, too. A nice toy if you can get it for $5, as I did, but not worth it otherwise.
Terragen produces truly stunning landscapes and skies, and there’s a free edition - but the free edition is limited, and the full edition is not cheap.
If you like working in DAZ Studio, the Infinito plugin lets you make landscapes. Unfortunately, if I remember correctly, not all features of the generated landscape can be saved, which may be a deal-breaker. Not free.
Personally, I alternate between Vue and Carrara these days. If I had to pick one, I’d go with Carrara. Vue produces much better landscape images, but Carrara is a better general tool. If you use DAZ content, you’ll also find the workflow for inserting figures into your scene much simpler.
Have I missed any?