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Multi-pass rendering problem with Diffuse layer in C4D r19
Hi, I am a newbie to C4D so I hope I am doing something stupid, but I would appreciate any help or advice.
I have been trying to render a simple animation (based on a Hello Luxx tutorial at https://vimeo.com/177569974). Everything is fine until I get to the output stage and try to render multi-pass files to import into After Effects.
In C4D, my diffuse renders look correct. They are like a relatively flat coloured version of the shapes in the animation. But the saved files (I have tried as PSD and PNG) are totally different. Only the edges of the objects appear, and they are all noisy and strangely coloured. When I import the files into after effects they look totally wrong because the diffuse layer is almost completely transparent.
I am hoping that this screenshot will help to explain. Why is the output file so different from the preview in the C4D render window? Can anyone with more experience spot what is happening to my renders? Many thanks in advance for any help you can offer.
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4 Replies
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I couldn’t see your images but… Do you have separate files checked in your render settings? If not the multipass will be batched into one file (per frame) and you have to extract each channel inside AE (use Extractor in the 3D effects menu – select the channels of the effect and that will open a dialogue that lets you choose what that layer will represent. You need to make a copy of the layer for each of your channels.)
I don’t think you can multipass a PNG the above way because it can’t hold multiple layers like a pshop file can but a png will allow separate files though.
There could also be an alpha involved – try interpreting the footage in AE and turn off the alpha. See what you get then. -
maybe a bug. try exporting as a 32bit PSD, I see it fixes it for me.
Roei Tzoref
2D/VFX Generalist & Instructor
♫ AeBlues Tutorials ♫
http://www.tzoref.com -
Hi. Just stepped into that issue, lost one render, and made quick research. PSD works fine of course, but the only problem is file size and not all render farms supports such big render file formats as PSD.
Uncheck “AlphaChannel” check box in RenderSettings panel under SaveRegularImage. It does the trick – diffuse renders normally. I can’t explain in any way, but it works.
If You need Alpha just add CompositionTag with one ObjectBuffer to all your objects and include it in the multipass tree as a separate pass.
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I also just realized what you were describing with the “noisy or wild edge”. This may be the Straight Alpha type at work. The Straight alpha choice is like a cookie cutter for your image. But if it were a true cookie cutter it would get a little bit of the black around the object due to anti aliasing and then you get that bad 70’s blue screen fringe. So instead it extends the colors of the objects edge pixels that, without the alpha applied, can look pretty psychedelic. Apply the alpha and matte it over something and all will be fine because the extended color insanity becomes the antialiasing at the edges so every edge pixel has the color of your object and none of the background you rendered it on (usually black).
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