The problem with Alt-Q is that FP still creates most of it's items even when the FP objects are not part of the isolated items - and even when no view or camera dependency is set. Annoying since ever, frequently mentioned (at least by me), never reported properly. This is one cause for this strange IR latency you get when IRing simple things.
Sometimes it helps to switch off the layer with FP objects to avoid this but sometimes the FP objects are processed even then. You can easily track this by activating FP debug mode ("General" -> "Log Level" -> "Debug" or "Normal") and monitoring the max.log file while starting IR. Besides of course you notice it because it takes ages to IR just a box.
I just found out the following while working for example:
- Have a layer with FP objects on it
- Have that layer collapsed and hidden in scene explorer (bulb off)
- Start IR -> All ok. FP reports NotifyPreRender start/end in the log without creating anything. IR starts very fast
then:
- Just expand that layer in scene manager, no other change! So that you see the (still hidden) FP objects in scene explorer
- Start IR -> ForestPro begins to build meshes for those hidden objects. WTF!
I'm still on FP 6.1.2 because of a bug which I have not seen fixed yet in later versions according to the Itoo changelog (Corona Ticket #16211 ForestPackPro Edge mode not working in IR when areas have keys), so it is possibly different in 6.2 - but I don't think so.
And again -as always- I cannot say on which side this should be fixed.
Good Luck
Can't say why is that happening to you. I use Forest lister which by far works very nicely, even I can hide/unhide forest scattered objects seamlessly during IR in progress. I am facing the infinite loading scenario during modifying forest options, for instance, changing random scatter to cluster mode or tweaking with "Distribution" or "Transform", etc. 70% of the time it works fine with IR with few extra seconds of loading 30% of the time it sucks. So, for now, I just stop IR, isolate the object + scattered area and once done with the tweaking I hit IR again. I am talking about a scene with 25+ million polygons, so I usually just keep my expectations low sometimes. lOl
Forest pack Edge mode is working perfectly with Corona. Just make sure that you apply forest edge. Select Forest > go to modify tab > Material > Optimize materials >Apply forest edge. You must apply it again after adding any excluded object. Maybe you know that but it works perfectly for me.