Lighting and reflection
A very good and extensive light tutorial
DIgital Tutors "Use Background" shader tutorial (again)
First of all: Turn off 'enable default light' in the render options!
We have to find our main light source which is the sun in this case. Look at the shadow on your sequence to find the direction of the sun and add a directional light or spotlight to work as the main light source. Here is a simple setup to see if the main light angle is correct:
-Add a 'use background' shader on the ground plane and either; turn 'specular color' to black, 'Reflectivity' to '0' or 'Reflection Limit' to '0' to turn off any reflection.
-Create a directional light and turn on 'ray trace shadows'
-Render with mental ray
Scene setup to test shadow angle
Optional:
-For a some quick ambient light and soft shadow turn brighten up the 'background colour' of the cameras' 'environment' setting and turn on final gather.
Scene setup with ambient light
Additional Lighting
If additional lights are needed they can be added at this stage. As a rule I use spotlights for additional lighting as they give you good control. Things to look into when it comes to additional lighting are; specularity options, shadow parameters, intensity and light-linking. When light setup is complete every part of the 3D element should be lit in some way or another. Avoid totally black areas and use the background plate as reference.
The Poor Man's LDRI Reflection
For those of us who does not have the time or money to create real HDRI environments let's try "the poor man's LDRI" method. If you've been following this tutorial you may recall the panorama image created earlier and that was not created in vain my friend.
Environment map to be used on a sphere
Our next step will be to add a spherical environment (create a sphere surrounding the scene and add the environment map to the sphere using a 'lambert shader') which primarily will act as our reflection source. You may have to invert the x- or y-axis to mirror the environment from the inside. Finally make your way into the 'render stats' and uncheck 'cast shadows' and 'primary viability' because we don't want it to show up in our renders and we don't want it to obscure our lights but still keep the texture information. To get lighting information from the sphere I recommend adding the texture into the incandescence slot and maybe turn up the 'value' of the 'color gain' in the 'color balance' of the texture.
Environment map added to a sphere in Maya
Align the spherical environment with the image plane sequence. Just to make life difficult the spherical environment makes the 'use background' shader unusable. As always there are workarounds but unfortunately this, as far as I know, requires a bit of compositing or rendering in render layers so I'll leave that for now and trust the spherical environment to be perfect!
It all comes down to how well your environment reference image is and unless your render involves highly reflective objects this alignment is not crucial.