Non-disappearing objects during render!
 

I am doing an animation where a character bends over and picks up a large placard. He holds it up for a few seconds and then bends over to put it back down. He stands up again and continues hand-gesturing without the placard.

Simple in theory. The placard (a simple Poly Cube) is parent-constrained to one of the character's hands. The visibility is "off" until he picks it up. The visibility is "on" for the duration of him holding up the card, and keyed to "off" again when he puts it back down.

The problem is when I render out my frames (.tiff format, using Mental Ray) , the damn placard is still visible AFTER it is put down, just sitting there at the bottom of the screen! (if anything, it should continue to move with his hands, as it is parent constrained)

For the record, it looks fine when I do a single frame render in Maya, and it works fine when I playblast the scene. It only glitches when I do a full-fledged batch render

There are a few possibilities here. I turned off default lighting in my render globals. Would THAT make a difference? I can't think of anything else.

I will add pictures when I get back from work tonight, but ANY help would be appreciated!!

Thanks in advance!

Here's the first picture, BEFORE he picks up the card

Here, he's holding the card. It is parent-constrained to the character's right hand

Here, he puts down the card. The card object (a poly cube) is keyed to "visibility off" a couple of frames later...

Finally, he gets back up and continues yakking. Problem is, the *&$^%( card is STILL there, and I can't seem to get rid of it!

BTW these are frames taken from the batch render. Frames individually rendered in Maya (under the same Render Global settings) seem to wqork fine, as do the Playblasts! Again, thanks in advance!

my only thought is that one of your keyframes got messed up somehow... check all your objects and make sure they're going on and off at the right times...

if that doesn't help, then you can always render out that last part after deleting the card so it just doesn't appear at all... then you can merge the two frame sequences later on in a compositing program.

Aye, I agree that NeoStrider's suggestion would be the simplest.

Another way it coule be done, yet require a wee bit of work, would be to redo a slight portion of those end frames, and make sure the doctor/character sets the placard ALL the way out of sight...

Or maybe do a wee bit of a camera move and/or zoom...but then again, you may like it the way it is and may not want to make such an adjustment (and I see that quite a bit of the placard is sticking up...>.<)

Thanks for the reply, guys!

For the record, I did in fact check my keyframes, and they definitely DO go on and off when they're supposed to...but ONLY in Maya! Again, it is only after a batch render that I get this strange result! :-)

I am going to first try activating the default lights and re-rendering, just to see if that might have been the problem (probably not, but you never know). Otherwise, your suggestions are quite valid. I don't wish to move the shot any, so I will probably go with a "cardless" render!

It just puzzles me why this would happen in the first place!

Thanks again!

Thanks again SeveriniAnthony and NeoStrider!

I tried a render with the default light on, no change. The card was still there.

I just tried a test render with the card removed at exactly the spot it was supposed to disappear, and it works fine. I will rerender the last 400+ frames without the *$^#(% card! (Since the camera was locked, the tiffs match up perfectly).

One odd thing...after deleting the card, I find I cannot save the scene (even after rebooting). I will have to check, but I may have constrained the card to a referenced object (the doctor character) rather than on the original. Maybe that has something to do with it! In any case, it won't matter, as the next scene is a completely different shot and the following scene will need to be recomposed anyway.

Whatever the case, this is a perfectly good workaround which doesn't require Herculean effort, so I will keep this in my bag o' tricks should it ever happen again!

Thanks again, shipmates!!!!