Use RGB_32F for color buffer.
Add simple linear mapping.
Convert color to linear space.
Add exposure parameter.
Use 150 lumen.
Add tone mapping.
wtf
Offer different tone mapping operators.
Add comment.
Disable settings of some uniform.

Disable setting of roughness, metalness, opacity and reflection. These are a bit
problematic.
Smaller lamp.
Merge branch 'feature/new_renderer' of github.com:vrsys/guacamole into feature/new_renderer
Change metalness to zero.

Metalness should either be zero or one.
Experiment with light parameters.