View Full Version : MDD only saves partial Bullet Solve

04-04-2016, 09:53 AM
I am building a scene in a mine environment where I dump a large cluster of rocks into a pile and an excavator scoops it up and dumps it into a haul truck. Fairly strait forward. So far I built 3 large clusters of different sized rocks in order to simplify things. I can run Bullet and everything solves beautifully. The problem is after I export the solves to an mdd file and try to reload it, only half the solve plays back. The rest of the mdd file looks like the point order changes or something and makes a huge mess of polygons off to the side. I have been trying to figure this out for a week now and I'm not getting anywhere. always the same result. I am using 2015.3 if that helps. The animation is about 1600 frames long. The mdd file seems to correctly save the first 300 frames or so while the rocks settle and the excavator starts to scoop before everything blows up.

And Ideas?

04-04-2016, 10:15 AM
Check your render output frames. I might be thinking of something else, but I vaguely remember something exporting if my frame range for rendering wasn't set to my scene length in the timeline. It went by that, which threw me for a while. It might have been motion baking, but it might have been for MDD's

04-04-2016, 11:38 AM
Cool! thanks for the suggestion. I fixed the frame range and Im trying it again. Ill post back with my results.

04-04-2016, 11:52 AM

04-04-2016, 11:58 AM
That would be excellent if it works! Let us know.

I'm a impressed such a complicated simulation, dumping then pickkup then dumping again, works at all. You must know, but if you get any small glitches I believe Chronosculpt (free!) would fix them faster than a re-solve.

04-05-2016, 12:45 PM
Is there a file size limit on MDD files? 1600 frames must generate a pretty big file. Are you running the 32 or 64 bit version of LW?

04-05-2016, 03:35 PM
Is there a file size limit on MDD files? 1600 frames must generate a pretty big file. Are you running the 32 or 64 bit version of LW?

If the LWO format has a 2Gb limit and FBX a 4Gb limit ( as I encountered last week) then I would assume that mdd also have a 2Gb limit, but I'm only guessing.

04-05-2016, 04:45 PM
So I think file size is indeed the issue. Everything is 64 bit but the mdd file is still about 20 gig :P

I did another test keeping the mdd file size around 4 gig (this seems to be the maximum stable file size) and it seems to work. So I guess the solution is break the rock pile into smaller pieces and bake them out separately.

Thanks for all your help! Hopefully this helps anyone else baking large mdd files as well.

04-05-2016, 04:47 PM
If you can, supply the LWG devs with this scene, so they can see how it breaks. With any luck, we'll all benefit.