I'm trying to learn a bit more about creating an ambient pass (global illumination pass?) in C4D for the purposes of video compositing a set extension in to a video clip. Based on an HRDI tutorial I found, I have done the following...
created a sky object
created a material for the sky object that is a filter layer in the luminance channel
containing the first frame of the video clip. I ahve adjusted the gamma to 2.2
rendered with radiosity on standard with default settings
The render seems pretty close but I have a few questions, perhaps someone has an opinion.
1. Is the most efficient method for creating this kind of pass?
2. If the final output is for NTSC, will it make any difference in quality if I render a 16 bit or 8 bit image?
3. I am using a non-HRDI image to do image-based lighting, do I need to make further adjustments to the luminance channel to compensate? Its my understanding that HRDI images contain a great deal more brightness information over a broader range would a video image be too dark for this purpose?
4. Should I stick to the default radiosity settings or can I get away with fewer samples or less accuracy give that the final output is NTSC
Thanks in advance for any tips. Also if anyone knows of good reference material on 3D compositing with either AE or Shake, I would be grateful if they could pass that info along.