As a quick example, just about everything watermarked by digitalblasphemy in this thread likely would have used some earlier version of Bryce in its creation
Bryce 7.1 is the latest version of the program, and is still available from its current owner/developer at:
https://www.daz3d.com/bryce-7-proBryce is currently $20, but previously it's been available during seasonal sales on the Daz3D site for less than $10
Do keep in mind that Bryce 7 is about 10-12 years old now, and it's only a 32-bit app, so it's limited to using only 2Gb of memory; however there is a highly recommended tool called 'Large Address Aware' that can be installed to increase the memory available to Bryce to about 3Gb, the tool and instructions are available at:
https://www.techpowerup.com/forums/threads/large-address-aware.112556/N.B. Because of its age, Bryce 7.1 is also completely incompatible with MacOS 10.7 and higher; Bryce may well NOT work on Linux either, so definitely do double check Daz3D's support pages and/or their Bryce forum (link below) before buying Bryce for your particular Operating System
Finally, for tutorials, info, tips, links, help, and contests, the Daz3D Bryce Forum can be found at:
https://www.daz3d.com/forums/categories/bryce-discussion#notsponsored
