Creating a Black Image with 3D Animation Software

This topic began as a serious discussion while trouble shooting 3D rendering software. This was back in the day when we would hit rocks together in a dark room capturing the light from the sparks on glass film photographic plates. ( in computer time it was close, the discussion was in the mid 1990's. ) The conversation spun into the ridiculous but still plausible. While rendering a scene this morning I was reminded of the whole deal and thought I would share a few ideas. Let's start with a few simple questions:

• Is there an object in the shot?
• Is there a camera in the shot?
• Does the camera creating the black image have the object in the view finder?
• Are you sure?
• Could there be two cameras in the scene?
• Which camera are you choosing to render?


Oh sure, these seem like fairly generic questions until you realize something simple is keeping from you from hitting the render button and subsequently asking the client for the check. Let us continue...

• How long did it take to create the black frame?
• Does the black frame in question have an alpha channel and is there information in it?


Before you begin yelling, "This program is full of bugs!", you may want to consider if the renderer is even working on something.

• Did the renderer spit the picture out in 0.0047 seconds when a similar object takes 10 seconds to draw?
• Did it take a long time to draw and is the image is the same color as the fog?


Here is a crazy idea:

• Does the 3D program create an error log?
• Did you read the error log?


Add to this list of generic questions a seemly unrelated question:

• Is it after midnight?
• Is it after midnight and you started on this project at 8am?


During large projects I've often said, "An hour of time after midnight is like 15 minutes during the day." When the brain is trying to solve a problem after many hours of working, then tiny, silly issues can become large hurdles.

A spin off of this trouble shooting path may also work with objects rendering incorrectly in a scene, especially when other objects in the scene are showing up with the proper shading. That topic is for another time.

Other ways to create a black image:

• Make sure the camera far clipping plane falls short of any objects in the scene.
• Turn the fog up so it occludes everything.
• All the lights are on but are set as negative lights.
• Oh ya, did you add lights and are they set to a color brighter than black?


Did a friend (certainly not something you would do :) ), stumble across a way to create a black frame? Share your stories!