the sky really is the limit.
with a good timber framer, and good engineer or design team, you can likely get anything you want to work... and of course $$ to pay for it all.

you don't mention what size footprint, what the program for the space is, how it will sit on the ground, etc. etc.

i'd recommend web searching for pavilion ideas, and then working with your local TFr and engineer (or calling on a specialist TF engineer or designer from the TFG, TFBC, or the engineering council) to come up with a buildable design based on your site, program, potential logs available, wind, snow, etc. requirements.