Bizarre Rendering Output - any ideas what went wrong?

[thickly]

I just decided to give Mental Ray a try since I have Max 2010. My renderer of choice has been Maxwell, but the project I am working on is a dimly lit interior, wood ceiling, lots of lights behind glass - aka a Maxwell nightmare.

 

So I spent the better part of yesterday setting up the lighting solution and finally got to a place I was happy with. My small test renders were rendering fine - so for my final I just bumped up the FG settings to "Medium" and the output resolution to 2000x1200, I watched a good portion of the FG map creation then went to bed. During the FG creation everything appeared normal, albeit slow - but when I woke up this morning this is what I was greeted with. It took a little over 7 hours to complete the render - I have 4 views that I need to do, so obviously I am a little tentative about wasting another 7 hours to end up with a useless result.

 

Any ideas what may have happened? Do you think maybe this was an isolated fluke, or do you think there is probably something wrong with the scene?

 

EDIT: just tried a smaller resolution render and got the same results, FG generated in "color", once rendering started each bucket went to this "black&white" result, and a red grid line remained where each bucket completed rendering. WTF!

Edited March 5, 2010 by thickly

[mattclinch]

in the render setup window, in the processing tab, you have turned on the diagnostic mode for sampling rate.

[thickly]

Matt - if you weren't in London I would ask you to come by and slap me! Thanks for the reply.

 

Now the next problem: My scene freezes halfway through translation - has done it the past 20 times I have tried to render it, causing me to cancel, close and re-start Max.

[mattclinch]

sounds like you're topping out your RAM when voxelizing the scene? try using BSP2 possibly, or a more optimised normal BSP, and make sure your scene is as close to the origin as possible. difficult to know what's causing it without seeing the scene.

Edited March 5, 2010 by mattclinch

[nicknitro]

I found that turning on your (if using Max and Mental Ray) Conserver Memory checkbox helps a lot when Max is trying to Use all of your Memory to render. It is under the Processing Tab and set it to (whatever memory limit you want). Its in mb's so 1500 (1.5 g's) etc.

 

Hope this helps

[thickly]

could that be possible - the scene only has 20k polys, I'm running x64 with 6 gigs of RAM. I do have a lot of photometic lights which is the only thing I could think is taxing, but it has translated fine before. I just tried switching to BSP2 like you suggested, but still hung up on the translation.

[nicknitro]

Idk maybe you have some corrupt geometry in there that MR doenst like. Double check your geometry and try out the Conserve Memory thats all I can think of.

[thickly]

hey thanks to both of you guys for your help. Did some trouble shooting and I think what was causing it was some missing UVW maps. I knew they were missing but since they were on objects that weren't visible, I just clicked "continue" through the warning dialog. I think the last few times I tried to render, the translation was hanging right at the point the "missing uvws" dialog would pop up - but instead of getting the warning window it was just freezing. I got off my lazy a** and applied the missing uvw's and it seems to be working now.

 

thanks again!

SD

[RevitGary]

I have a couple tricks that might help when new to mental ray.

I seemed to have experimented with so many settings that I forgot what setting I tweaked and why.

 

Something I did that helped a lot was to get max back to it default settings. You can do this 2 ways. Save a back up file then

 

1. Set the render engine to scanline then set it back to mental ray

 

2. Open up a new scene and merge the geometry in.

 

You can then reapply the settings you know you want and the tweaks you forgot about wont be there. I think importing into a new scene sorta purges the file.