The rest is radiosity. No need very high as interior scene.
radiosity {
pretrace_start 0.08
pretrace_end 0.005
count 72
nearest_count 6
error_bound 0.32
recursion_limit 8 // this is important cannot too low
low_error_factor 0.5
minimum_reuse 0.015
brightness 1
adc_bailout 0.01/2
}
