Configurações - Photon Mapping (GI) and DIffuse Bounces (FG)
Autor: Emerson Oliveira Costa | Publicado: 2016-04-29T21:38:00-03:00








&nbsp; &nbsp;&nbsp; &nbsp;Para usar o Photon Mapping (GI) deve ter em mente que é necessário uma quantidade suficiente de Photons na cena de forma que cubra toda a superfície de cada objeto, e o raio dos Photons deve ser de um tamanho onde não seja maior que a espessura desses objetos. Obviamente se for o caso de objetos com espessura muito fina acho melhor ignorar, pois do contrário irá necessitar de uma quantidade enorme de Photons, e isso irá causar um aumento drástico nos cálculos de renderização. Uma boa opção é tentar manter com raio entre 3 a 5 cm. Este tamanho está relacionado a uma cena interna de arquitetura (uma sala, cozinha, quarto, ou ambientes com tamanhos semelhantes).

Average GI Photons Per Light - define a quantidade de Photons emitidas por cada luz da cena. Se houver quatro (4) luzes e nas configurações houver 250.000, então serão 4 luzes x 250.000 Photons = 1.000.000 de Photons.

Maximum Sampling Radius - define o raio dos Photons.

&nbsp; &nbsp; &nbsp;&nbsp;
Average GI Photons Per Light - Skylight Mode FG and IBL



IBL &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;on &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; on &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;on

maximum num. photons per sample &nbsp; &nbsp;&nbsp;100 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 100 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;100

maximum sampling radius &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 15cm &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;15cm &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 15cm

average gi photons per light &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; 20.000 &nbsp; &nbsp; &nbsp;200.000 &nbsp; &nbsp; &nbsp; 2.000.000 &nbsp;&nbsp;














&nbsp; &nbsp;Nas imagens acima, veja que com 20.000 photons não foi o suficiente para preencher toda a cena. Com 200.000 ficou razoavelmente bom. Com 2.000.000 ficou muito bom, mas veja que aumentar muito a quantidade de photons também irá aumentar no tempo de cálculo na renderização.






IBL &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;off &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; off &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; off

maximum num. photons per sample &nbsp; &nbsp;&nbsp;100 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 100 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;100

maximum sampling radius &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;15cm &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;15cm &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 15cm

average gi photons per light &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;20.000 &nbsp; &nbsp; &nbsp;200.000 &nbsp; &nbsp; &nbsp; 2.000.000&nbsp;&nbsp;















Maximum Num. Photons Per Samples - Skylight Mode FG and IBL





IBL &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;on &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; on &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;on

maximum num. photons per sample &nbsp; &nbsp;&nbsp;10 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;100 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1.000

maximum sampling radius &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;15cm &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;15cm &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 15cm

average gi photons per light &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp;&nbsp;200.000 &nbsp; &nbsp; &nbsp;200.000 &nbsp; &nbsp; &nbsp; 200.000&nbsp;&nbsp;&nbsp;























&nbsp; &nbsp;Em Maximum Num. Photons per Sample se deixar no valor 10 torna mais difícil para a mesclagem dos photons. Com valor 1.000 pode haver aumento considerável no tempo de renderização, e com valor 100 é o suficiente para que, usando Final Gather, possa suavizar os photons.





Trace Depth Max. Reflections / Refractions



IBL &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;on &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;on &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;

maximum num. photons per sample &nbsp; &nbsp;&nbsp;100 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 100 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;

maximum sampling radius &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;5cm &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;5cm &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;

average gi photons per light &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;20.000 &nbsp; &nbsp; &nbsp; &nbsp;20.000 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;



(trace depth)

max. reflections / refractions &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 10










&nbsp; &nbsp;Em Trace Depth mantendo os valores de Max Reflections / Refractions em 1 faz com que os photons possam refletir somente uma vez após ser emitidos da fonte de luz. Deixando no valor padrão (10) faz com que os photons possam refletir dez vezes após serem emitidos da fonte de luz. O mesmo é válido para de refração.





Maximum Num. Photons Per Samples x Maximum Sampling Radius





IBL &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;off &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; off &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;off &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; off &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;

final gathering &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;off &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; off &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;on &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; on

maximum num. photons per sample &nbsp; &nbsp; &nbsp;100 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 100 &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp;100 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 100&nbsp;

maximum sampling radius &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;10cm &nbsp; &nbsp; &nbsp; &nbsp;2,5cm &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;10cm &nbsp;&nbsp; &nbsp; &nbsp; 2,5cm&nbsp;&nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp;

average gi photons per light &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;200.000 &nbsp; &nbsp;3.200.000 &nbsp;&nbsp;200.000 &nbsp; &nbsp;3.200.000 &nbsp;





Photon Mapping













&nbsp; &nbsp;Deixar os photons menores e aumentar na quantidade mantem um GI com mais qualidade, porém é bom não exagerar para não aumentar muito no tempo de cálculo dos photons. Prefira manter o raio em 5cm e indo aumentado a quantidade até cobrir toda a cena.





Photon Mapping&nbsp;+ Final Gathering















Final Gathering (FG) and Diffuse Bounces



IBL &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;off &nbsp; &nbsp; &nbsp; &nbsp; off &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;off &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; off &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;off

initial fg point density &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0,1 &nbsp; &nbsp; &nbsp; &nbsp; 0,1 &nbsp; &nbsp; &nbsp; &nbsp; 0,1 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0,1 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0,1 &nbsp; &nbsp;

rays per fg point &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;50 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;50 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;50 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;50 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 50

interpolate over num. fg points &nbsp; &nbsp; &nbsp; 30 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;30 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;30 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;30 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 30

diffuse bounces &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;0 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 1 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;2 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 4 &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 7

























&nbsp; &nbsp;O diffuse bounces do final gather não seria uma melhor opção para cenas internas do que o photon mapping. Pode ser mais simples de se configurar, mas a qualidade é inferior. Há uma maior ocorrência de manchas e o tempo de renderização é bem maior.