I received a question the other day that was asking how I would approach painting out lights from LatLong HDRI’s that are near the bottom or the top of the image. Anything near those poles will usually be heavily distorted and are a pain to remove if you try to paint on the original map. However there’s quite an easy way to remove them in Nuke and at the same time get the lights to a nice and rectangular format for using them on area lights.
Image based lighting often times simplifies getting started with a good lighting setup when trying to integrate CG into life action. Often times it’s beneficial to have the IBL sphere to just contain the ambient lights from the environment and therefore to paint out any actual light sources from the set. Those can then be used on separate lights to give the main illumination from the set lights, while the IBL sphere contributes ambient environment light. Now, if you have a lot of different environments and consequently a lot of different HDR’s it can be tedious to paint out the lights and output them after that…
Sooner or later there’s always a project where lot’s of things have to be removed. Sometimes there’s not only the quantity but also the quality of work required to get good looking results. There are probably not a lot of people out there who love doing this, but it has to be done, so here are a few snippets of tips I learned over the last few months.