Poser 6 Ambient Occlusion Samples
Preface: Because Poser 6's measurement units effect the values below,
you will need to switch your measurement units to meters in your preferences.

Note: All of these settings can be found on the Light Properties Panel.

Note: Values under renders are listed as: Max Distance/Bias/Num Samples




No Ambient Occlusion

To study the role of Max Dist, let's look at these different renders.
Only the Max Dist parameter will change...





AO MaxDistance: 0.1 Bias: 0.001 Num Samples: 1






AO MaxDistance: 0.2 Bias: 0.001 Num Samples: 1





AO MaxDistance: 0.3 Bias: 0.001 Num Samples: 1




AO MaxDistance: 0.05 Bias: 0.001 Num Samples: 1


"OK. The bigger Max Distance is the bigger the shadows are.
Too large a value can produce nasty shadows so beware!
Now let's see how bias works...





AO MaxDistance: 0.05 Bias: 0.002 Num Samples: 1




AO MaxDistance: 0.05 Bias: 0.0005 Num Samples: 1




AO MaxDistance: 0.05 Bias: 0.00025 Num Samples: 1


With low values we get some black spots: render artifacts.
Let's try a better compromise: 0.00075.





AO MaxDistance: 0.05 Bias: 0.00075 Num Samples: 1

Ok. The bias works fine with 0.00075. Lower values are risky...
Now let's study the influence of Num Samples.




AO MaxDistance: 0.05 Bias: 0.00075 Num Samples: 5




AO MaxDistance: 0.05 Bias: 0.00075 Num Samples: 10

Lets try with other Max Distance Values:





AO MaxDistance: 0.2 Bias: 0.00075 Num Samples: 5




AO MaxDistance: 0.2 Bias: 0.00075 Num Samples: 10

The influence of Num Samples is really not obvious to me...

To conclude 1- Max Distance set at 0.1 is fine. Greater values will create artificial shadows. Lower values will produce less shadows.
2- Bias set at 0.00075 works well. Below, you risk artifacts. Upper values will work of course but the lower the bias is, the better it is, isn't it?
3- The Num samples is a mystery for me. This must never be forgotten!