particle streak compositing...

# 1 05-04-2005 , 03:22 PM

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Join Date: Feb 2005

Posts: 18

i am not actually sure where this post belongs because there is no compositing feature in maya...i am having problem however when i composite a sequence i rendered out in maya.

the sequence goes as follows:

1. software rendered the acutal scene and the objects contained within

2. hardware rendered the rain, which was constructed out of particle streaks

3. applied an luminance alpha channel to the hardware render for the sake of compositing the two renders together

4. the image of the rain alone looks fine...but when composited with the acutal scene the rain loses its visual intensity and fades in color tremendously.

is this because of the luminance alpha channel?...does anyone know how to correct this...

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# 2 05-04-2005 , 07:24 PM

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Join Date: Sep 2002

Location: London, UK

Posts: 3,198

You could try to boost the alpha in post. Adjust the levels or something. What application are you using for compositing?

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

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# 3 05-04-2005 , 11:52 PM

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Join Date: Feb 2005

Posts: 18

im using after effects to composite the sequence...the fact that the rendered images already have established alpha channels, when i layer them in after effects i dont really do anything but the images automatically sync/merge...very basic i know...but my experience with compositing is limited to just a few weeks

...again...any help would be much appreciated.

...ive tried actually increasing the levels in photoshop...but when i re-composite the shot it dulls down the rain again.

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# 4 06-04-2005 , 08:11 AM

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Join Date: Sep 2002

Location: London, UK

Posts: 3,198

Well, you could select your rain footage in the project window and press ctrl+f. In the Interpret Footage you could set Alpha to Premultiplied. Also in your composition you can add an Alpha Levels effect to your rain and adjust the Gamma.

Kari
- My Website
- My IMDB

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

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