Orchid XP v3 nous apporta ses lumieres en ce 03-01-2007 14:03:
>>> Yeah, each light source is a 16x16 area light. Given that the tree 
>>> has hundreds of thousands of tiny needles - wait, just read the 
>>> render stats! Look at the number of shadow rays, for crying out loud! 
>>> o__O
>> Over 4 BILLIONS!
> 
> Hell yeah.
> 
>>> I did also try this with radiosity - but it makes absolutely no 
>>> visible difference. (Well, given how puny the light sources are, the 
>>> extra bounces don't contribute much.)
>> As Christmass lights are geting smaller and smaller, actual 
>> point_lights should be "good enough", especialy if you have 100's of 
>> them.
> 
> With point-lights, the walls are covered by giant needle shapes. It 
> looks very bizzare and unatural. With area lights, the walls are motled 
> with shades of light and dark - go look at a real tree, this effect is 
> actually pretty much right on!
> 
> Now, if I actually had *hundreds* of lights on the tree, maybe it 
> wouldn't matter... but most sets of lights contain 20 or 40 lights, not 
> several hundred. ;-)
Just with 12 to 40 the need for area_light will go down, crank that up to 60~80 
(3 or 4 sets of 20) and you probably can say area_light good by!
> 
>> Don't forget to set fade_distance to a suitably small value.
> 
> Already done. 50 cm. (Fading = quadratic.) This makes a big difference...
> 
>> If manual placement is to tedious, why not try some procedural 
>> placement, maybe integrated in the building of the branches.
> 
> I don't know what algorithm TomTree uses to built the branches.
OK! It's not your own tree. Harder to selectively remove elements.
> 
>> In real life, the lights are often placed between branches.
> 
> Yeah... maybe I should just wrap a "string" round the tree and use a 
> physics simulation to let "gravity" position the string? (I can use the 
> trace() function to make it stop when it hits a branch.)
> 
> OTOH... it's not going to be fast!
> 
>> If the parceing gets to long, why not use a switch to turn off the 
>> needles while you place and test the lights?
> 
> Already doing that. Takes 30 seconds to parse even without the needles. 
> (Can't turn the detail down any further because I need to see where I'm 
> placing things!)


-- 
Alain
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Fine day to work off excess energy.  Steal something heavy.

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