Slow interactivity in Houdini

[SimonLundberg]

Interactivity in Houdini's LOPs workflow using the RPR delegate is very slow in 2.0 ("Full") versus the previous version ("Full (Legacy)"). The other quality modes also have pretty slow interactivity. Note that I'm not talking about noise or convergence time or anything like that, but rather the frequency at which the display updates when navigating or moving objects. I haven't measured but I'd estimate around 1-2 frames per second on a very simple scene, versus maybe 5-10 in the legacy mode. Note that this is even on a scene consisting of a single low-poly grid.

See linked video for a demonstration. The modes shown are, in order: the new "Full" mode, the old "Full (Legacy)", and Houdini's built-in renderer Karma. Karma, being completely CPU-powered, is the slowest of the three, but the rates of interactivity are far beyond either RPR mode.

https://www.dropbox.com/s/41xz1wlffha1nut/Rpr%20Interactivity%20Slow%201.m4v?dl=0

[hshakula]

I know that feeling.

I can tell you that 80% of the time needed to render the very first frame with Full in 2.0 is not an actual rendering. I'm pushing this problem internally as much as I can.

I will let you know when I will have news.