One of the hardest parts of doing CGI is the semi-final render - days of waiting for the computer to calculate all the light interactions and the image is 90% done and suddenly - the raytracer miscalculated what was what and some object in the scene looks like an invention of M.C. Escher and you have to figure out how it miscalculated it, fix it, and then wait many more days to see if it actually got fixed. So much waiting - and patience is not a virtue, it's an imaginary attribute of imaginary creatures that don't have to deal with computers.
I'm surprised it still takes days to render on a modern computer. A CNC toolpath that I waited half an hour for in '98 takes a few seconds now. How fancy a render are you doing?
It has tons of water, about 26 light sources and - I will NEVER do this again - a wall of plate glass with all the optical properties. Much reflections and refractions.
Some of the things that REALLY increase the time (from a few hours to many days) are enabling both "ambient sky light" and "Indirect light" which sound like similar things but aren't. Indirect lighting is usually only useful in indoor scenes. Takes into account the light scattering properties of objects to get a more realistic ambient light effect. "Sky Light" simulates outdoor lighting (notice how shadows are not completely black in the presence of an atmosphere?). SO - in a scene with indoor AND outdoor elements, both need to be enabled to get the best, most realistic, lighting. And the computer spends FOREVER calculating all the possible interactions. The glass in between magnifies the problem, because it is both a source and a target of indirect light, and it also needs to account for light from the others side. On top of that is the big tree outside the window with hundreds of leaves, the swimming pool with the optical properties of water (which is on the other side of the window so even MORE fun indirect target/source light issues), and high-res (high polgon count) model of the subject person.
It looks really good, too. I must confess I was surprised at it still taking days, but that's because you're doing things that most of us wouldn't have even bothered trying to do before :)
Thank you :) I is fanatical about light being right :) I'm too sensitive to it, yet it bothers me to see it 'wrong' in images.
Trying to make a new character (for a story) and finding it hard to get her face right. I keep slipping back to my fave look for young women and it is very not right for this character. I think I have a fixed impression in my head of what a 'young' face looks like and since I don't look at faces RL it is really hard to get past that and make the face the text describes. I'm getting enough variation that the person doesn't look "same face", but the gross features (forehead shape, cheeks, etc) are tending too much toward that. Not precisely a CGI issue, but since that is what I'm using as a tool ...
And part of it seems to be using my "default pose and camera angle" for the testing. Finding some good pics to use for reference, plus reposing the model, and I is making progress again.
