Tips for optimizing scenes/materials for IR?

[Monkeybrother]

IR works very well for simple scenes, but if I introduce scatterers and/or trees, IR just isn't an option anymore. In many cases Max just gets stuck in a loop and I have to restart it, or sometimes the computer, to get it back on track (for a while). Of course it's going to be slower with more comples scenes, but I'm wondering what exactly is the heaviest for IR; is it the sheer amout of geometry, or is it something else, like the opacity maps on the leaves for example? IR seems to hate Evermotion trees the most, but I have heavier tree models from other vendors that seem to work better.

[Ondra]

there are currently some bugs that slow down interactive, we will fix them in 1.6 ;)

[Cheesemsmsm]

there are currently some bugs that slow down interactive, we will fix them in 1.6 ;)

Could you (or someone) tell me what are the causes of the bugs and how to avoid them in 1.5 (if possible) ?

[Ondra]

one can be easily avoided by not using 3dsmax physical camera for IR, second by not using 3dsmax 2017 ;)

[pokoy]

one can be easily avoided by not using 3dsmax physical camera for IR, second by not using 3dsmax 2017 ;)

For me, it's also Corona's CameraMod which lags similar to the Physical Camera in 2016.
2017 - didn't notice this yet but if 1.6 fixes it, even better ;)

[Monkeybrother]

one can be easily avoided by not using 3dsmax physical camera for IR, second by not using 3dsmax 2017 ;)

That would explain things, we use both. So it's better to use IR with a simple "perspective" viewport? Or do you still get the same slowdown if you use 2017?

[pokoy]

Perspective works fine for me, as for 2017 I haven't used it much so better do some tests first.

[Dalton Watts]

I have to say that IR works fine for me. Miles faster than Vray IPR! I use a dual Xeon 2696v3 setup and i don't have any problems with Evermotion trees also.

[Juraj]

I have to use the CoronaCam mod trick to make IR usable, seriously, I didn't know about this until someone mentioned it on group chat : /.
That actually solves it quite well for 2016 that I use.

The initial start-up can sometimes be a bit sketchy, doing few freezes/loops, but once it starts it's quite solid. Although yesterday it kept restarting after every 10 passes or so... not sure what caused that.

[Monkeybrother]

I have to use the CoronaCam mod trick to make IR usable, seriously, I didn't know about this until someone mentioned it on group chat : /.
That actually solves it quite well for 2016 that I use.

What is the CoronaCam mod trick?

[Ludvik Koutny]

There's also a bug that causes loop of very slow updates when selecting mesh some objects are scattered on.

[Juraj]

I have to use the CoronaCam mod trick to make IR usable, seriously, I didn't know about this until someone mentioned it on group chat : /.
That actually solves it quite well for 2016 that I use.

What is the CoronaCam mod trick?

You apply CoronaCam modifier to your Physical camera even if you don't plan to use it anyhow.

(just beware that even if you don't use any feature from it, it still overrides the DOF effect with the f-stop number )