FPrime ghosting when refining

[Boris Goreta]

Ok, one of the best features of FPrime is that you can stop the render anytime, and then continue it without loosing what was allready rendered. Unfortunately I just did that yesterday, but when I restarted the renderer to refine frames some more I have noticed ghost copies of objects in the final output. That destroyed 20 hours worth of previous rendering so it's not good. This ghosting happened because I had cars in the scene which were animated using LW, they had simple motion applied to them. Now I know from previous posts that I have to apply dummy displacement map transformation to all moving objects. Is there a plugin that would do that for all objects in the scene ? Is there another workaround ?


Using LW32 9.3.1 on Vista64 dual X5365 8 GB RAM 8800GT

[Lewis]

Any screen grabs ?

[Taran-Q]

Had the same problem quite a few times. Mostly render highres stills. Whenever rendering only one frame at a time no problems. But sometimes when rendering multiple frames (no animation just different cam angles/positions, no moving objects!), fprime seems to mess things up. It shows ghosted images of previous frame in render or just ghosted objects in strange positions. Very weird....
Gonna make some screenshots next time it happens... but it looks just like a double exposed photo.

As we tend to switch from LW version every now and then for different reasons I'm not quite sure which combination of LW/fprime was used.

[Boris Goreta]

Ok, I made an ultra simple test scene and the problem is recreatable. There is one animated object in the scene and it is parented to the null which is also animated. Load the scene and start FPrime renderer with infinite refinement. Stop the renderer after all frames have been rendered to some point. Exit LW. Reload the scene. Start the renderer again to REFINE existing frames. Let it cook for a while. Periodically check rendered frames and you will see rubish. The object has been ghost, duplicated or however you want to call it. IMHO this is a very simple setup so it shouldn't be hard to track this VERY DANGEROUS bug. I say dangerous because it can corrupt your previous render just when you think "Oh, the render looks nice but I will refine it just a little bit more before the client comes." , and then when the client comes all you've got to show is rubish. Now, if Worley is on a long vacation can somebody from Newtek please fix this. I think this is totally doable. Why ? Because you can avoid this problem if you click on the Displacement Map T box under the Deform tab of the problematic object. This way LW somehow sends correct data to FPrime or FPrime correctly snoops data from LW. So, programming wise it shouldn't be a big deal to solve this BIG problem. I am sure there are plenty of other poor souls out there coping with this problem in everyday production. Otherwise FPrime plays very well with LW and I am very satisfied with both of them.

[Taran-Q]

Nice to have a scene that actually reproduces this bug. The times I had to deal with this, it was just random. Just start the render over and hope it turns out ok (pretty frustrating facing a deadline :( ). Also in my cases the render wasn't paused and resumed afterwards, so i was guessing more in direction of objects/camera parented to a null. The scene's that went wrong here too had objects/camera parented to a null, nothing else 'special' in the scene.

[Taran-Q]

And like i said it only happens when rendering multiple frames. Never had any problem when rendering just one frame in a certain scene.
Before i leave office i check the render's first passes and everything looks ok. When I arrive next day renders are messed up by ghosting content...

I included a render from bgoreta1's test scene

[Taran-Q]

attachment

[Lewis]

And what Mr. Worley says about that? Anyone reported to him ? Semes like FPRIME issue and not LW or?

[Boris Goreta]

For now you can check Displacement Map T box for every object in the scene and the problem will go away but I allways miss some object in big scenes which makes my render useless. :thumbsdow

[Boris Goreta]

This is from Worleys site:


Known LightWave Issues

* A LightWave bug in LW 9.0 and earlier can cause objects with motion plugins or tracking to appear in the wrong places in FPrime. This bug is fixed in LightWave 9.2.


And I can confirm that there was a period when this was working allright but then it came back with a vengance during some of the 9.2. betas. It doesn't make sense to mail this bug to Mr. W since he clearly stated it was a LW bug. But I fogged it.

[Taran-Q]

I'm pretty sure it happened in LW9.2 here, and we have no motion plugins applied.

[Taran-Q]

For now you can check Displacement Map T box for every object in the scene and the problem will go away but I allways miss some object in big scenes which makes my render useless. :thumbsdow

You mean adding an (inactive) displacement texture??

btw nice flying buildings :D

[Boris Goreta]

Yes, inactive displacement texture.

But Taran, that is your nice flying building, I posted test.lwo which is just a stick. LW probably took test.lwo from your current content dir. :) :) :)

[Taran-Q]

LOL, need to avoid using objects named test.lwo :D:D

[meatycheesyboy]

I just started having this problem yesterday with a scene and noticed something odd. After I had the problem, I saved the scene, shut down LW and reloaded the scene. The problem still existed AND some of my objects were set to 40% dissolve that had no dissolve setting on them before.

Also, my scene doesn't have anything parented to a null but it does have objects parented to other objects.

Running 9.31, has anyone found out anything new concerning this bug?

[edit] It is a sequence of frames and does it in render only at first but then preview gets messed up after the problem presents itself for the first time. [edit]

[Taran-Q]

Unfortunately the dummy texture displacement trick doesn't work here.... It still messes things up in certain scenes and I can't seem to figure out what the problem is.
Strangely enough it seems to happen more often on some machines than it does on others....
LW 9.3.1 Fprime 3.01

[pooby]

It will also screw up if you use Fprime render when objects or view is in Bounding Box mode.. switch to wireframe or textured or something and it should fix anything that can't be fixed by adding a dummy replacement.

[Taran-Q]

No objects or view in bounding box mode here .....