VFX techniques research

This project is going to include a significant amount of VFX work.  I have been working on identifying what Visual Effects and CG elements will be needed for each shot.

So far we are looking at adding Blood effects, Sky replacements, Set extensions, CG props, and CG buildings.  A number of shots will use the greenscreen and then be composited together later.

With this is mind I have been looking at a few different tutorials online to get an idea of how other people might approach some of these tasks.


This is a Sky replacement tutorial which uses a Channel Key and Garbage matte on a still image to replace the sky.  This technique is fairly basic, and could be adapted for use on filmed footage.






This next tutorial is a Sky replacement which uses geometry with a sky texture applied and a camera track to help integrate the sky into the moving footage.  It isn't a brilliant tutorial but gives a good starting point and some ideas to work with. The first two parts of this tutorial focus on preparing the sky. 




In our project we are going to be compositing skies created in Vue.  I am wondering about the use of camera tracking and how this data could be brought into Vue so we could render out the correct movement.  This clip shows a Nuke/Vue workflow, and it seems that the camera from nuke can be imported into Vue scenes.




Some test footage is being filmed for me at the moment so once I get hold of that I will begin testing out some of these methods.  This should give me an idea of any issues that may crop up that I should be aware of before we begin the shoot.