On 2019-10-10 2:33 PM (-4), Alain Martel wrote:
> Le 2019-10-09 à 20:55, Cousin Ricky a écrit :
>>
>> This was a 3-pass render:
>>
>>    1. A photons pass with no trees on the hills.  For some reason, the
>>       shooting of photons stalls when the trees are included, though I
>>       cannot see how the trees would interfere with the process.  It is
>>       only a small section of the checkered plane that receives
>>       photons.  ("Either be patient or do not shoot photons at infinite
>>       objects." --Reference Manual)
>>
>>       Photon mapping was also faulty with the scene as-is, but when I
>>       inserted a patio into the scene, the photons were perfect.  I
>>       couldn't figure out why that is.  The patio was removed for the
>>       final render.
>> [snip]
> 
> For those trees and photons : You can set the trees so that they don't 
> receive any photons with : photons{collect off}
> 
> You can replace the trees with some place holder in the initial phases.
> 
> Even for the final pass, it may be possible to use a «billboard» that 
> show the trees.

This was the setup for the photons pass render: a texture used as a 
place holder for the trees, and no radiosity.  Also, the actual run was 
smaller and without AA, but I would not inflict that image on you.

   Number of photons shot: 159843404
   Surface photons stored:  27846963
   Gather function called:     67275

The trees (and the patio, for that matter) came from an include file, 
and it would have been difficult or impossible to set collect off on 
them.  But again, the interference just didn't seem to make sense.  The 
photon count just stalled forever at a few thousand (in contrast to the 
millions in the successful render), and few if any photons would have 
hit the trees anyway.

There is a bit of caustics on the patio wall, but it didn't show up in 
the final render.

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