Apache render problem

# 1 28-03-2005 , 01:05 PM

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I have run into another problem with my Apache animation, right at the last hurdle! I rendered my Apache (yes it took 20 hours) and everything looks fine. The alpha channel is there and there is no jitter or flicker. However, now I am compositing it in DF (4.04c) it won't show up using a merge node? I can get the background and shadow to interact with each other, but no matter how I connect it, or indeed where in the order I place it, the other sequences mask it out? If I turn the alpha gain up it becomes visable, and I can play about with the tranfer types (multiply, overlay etc) and get it to view a bit better. I have obviously rendered it incorrectly somehow and I did render it on another machine using a copied scene file (probably should have imported it) but I can't figure out what's wrong. I will probably render in again on the computer the scene file was created on as I don't seem to have any trouble with the background and shadow renders which were done on it, but can I find out what may be going on, and can I fix it with a batch render in Photoshop?
Thanks in advance for any help
Smokey B

There are 11 types of people in the world, those you understand binary, those who don't and those who have a life (my own variation)

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# 2 28-03-2005 , 02:54 PM

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Ah Ha! I did a couple of 2 frame renders to see if I could fix this problem before a full re-render, and one exactly how Kari indicated and one without the Z-Buffer. The first does exactly the same thing as the problem above, but the one without the Z-Buffer will display normally as a forground to the background render. However, if you put the shadow render in between, it again masks out the chopper. This seems to be a problem with the alpha channels and I would love to hear some suggestions as to a solution. I don't have any compositing programs other than Digital Fusion, so I can't cross-software check this problem out, so can anyone suggest any others that may have a trial period?
Thanks

There are 11 types of people in the world, those you understand binary, those who don't and those who have a life (my own variation)

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# 3 28-03-2005 , 03:45 PM

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Ok, I've fixed it. The problem was (or seems to be): is that I didn't render the background and shadow with a Z-Buffer, I presume then, that all the layers cannot be seen through. I did a single frame with the BG and one shadow both with the Z-B (my Chopper already has a Z-Buffer and at 20 hours, thank god it has!) and composited them in DF, and all works perfectly now. I will go back to see if Kari makes any mention of this Z-Buffer issue as I may well have missed something.
Thanks
Smokey B

There are 11 types of people in the world, those you understand binary, those who don't and those who have a life (my own variation)

Last edited by smokeyb; 28-03-2005 at 03:54 PM.

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# 4 29-03-2005 , 12:18 AM

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Oops... saw this thread a bit too late it seems. I honestly don't remember what I did in the tute anymore user added image

DF has had some issues with alphas not loading properly. Playing with depth merge and depth offset in DF may help sometimes too...

Anyhoo, in the future you could take some screenshots of your problems as it's sometimes hard to get a picture of what's going on...

Kari
- My Website
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Do a lot, Fail a lot and Learn a lot!

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# 5 31-03-2005 , 09:31 PM

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Thanks Kari, but rendering the background and shadow with th Z-Buffer corrected the problem completely. I basically understand the Z axis inclusion but I thought the use of the alpha channel would create the same effect? But I am no expert on the subject.

On a brighter note the final render is fantastic, if not far too similar to yours. I of course intend to use the techniques you have taught me, and elaborate and develop the 12 second example, and all in all this was a superb series of tutorials (did all 3). I would however like to offer some feedback on the tutorials for you and the wider community, as there are parts that really confused me for ages. The good part about that is that it forces you to think for yourself, and I learned just as much by pondering a problem as I did when learning a method. I will structure something coherent when I have a couple of hours spare, but please don't take anything I say as critical of you, as I truly enjoyed every minute of it.

One last thing; are you going to do the last animation tutorial, the one about particle thingys etc, as I'm afraid I am not experienced enough to work it out from the short overview you give. I would love to finish this beast once and for all, but I feel like it's not quite there yet. I am in the process of searching other resources on the subject to see if I can get something similar, but it would be fantastic if you could do one specifically for this project, and I am fully prepared to beg for it....

Thanks again Kari

There are 11 types of people in the world, those you understand binary, those who don't and those who have a life (my own variation)

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# 6 01-04-2005 , 09:36 AM

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Thanks for the kind words and feedback, which is always welcome! Lately I've been very busy with other stuff and haven't had the time to do any tutes. No. 1 priority is to find a job or start my own company (<- been working on a business/financial plans etc.). If I get some free time I will do a series of tutes on particles. I got few other tut ideas in my head too. Just need to find some time...

Congrats on finishing the Apache!

Kari
- My Website
- My IMDB

Do a lot, Fail a lot and Learn a lot!

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Apache render problem

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