Render times changes dramatically with differents environments

Super cheese sandwich

My render times with five characters and a large environment (urban sprawl3) is 1 min but two characters and a small environment (bus stop) is 15 min! What I'm doing wrong? I'm using iray

 

Thanks

Richard Haseltine

Is there a dome blocking the environment light? Is there a dome stopping the rays from escaping to infinity? Is the sceen full of relatively reflective surfaces, that will allow rays to bounce around for longer before they attenuate to the point of being taken as final? One thing to experiment with is the Maximum Path Length under Optimisation in Render Settings (equivalent to the ray trace bounces in 3Delight, though I think it counts every interaction and so needs a higher value than the 3Delight setting - at least 6 for human eyes to resolve properly, for example).

FirstBastion

There are alot of variables at play when someone renders a scene. But all things being equal,  the odds are you're not doing anything wrong,  Stonemason (urban sprawl 3) builds very efficient models, (smart poly counts, proper render settings)   so the render times will be considerably lower than other model makers that do not build efficient models.  It's always a good idea to render a scen empty first to establish a benchmark for render times,  and then add your character figures to see if the culprit is the scene itself or the character figures or hair models added.  Reflection, refractions and transmaps alway add to render times.