Fuchur Posted July 10, 2009 Share Posted July 10, 2009 I have a problem with lightening an acryl-block with an image behind it in A:M. The best result I could archieve till now is a Radiosity-rendering, which looks great except the dark parts behind the acryl-block. Anyone can give me a hint to what to do next? I cant increase the sample-area or the amount of photons (A:M seems to have a limit here). I attached the consolidated projekt (had to replace the image with a dummy-image... but that doesnt matter... The rendering here is a progressiv-one, but it although looks like that in final-rendering. I am talking about the chor "Radiosity_Acryl" here. There I am combining Arealight-Shadows with Radiosity. Thank you very much in advance! See you *Fuchur* acryl_block_forum.zip Quote Link to comment Share on other sites More sharing options...
photoman Posted July 10, 2009 Share Posted July 10, 2009 300000 for the sample area is WAY high (I use around 2500 max on my outdoor radiosity scenes), that could be the reason for the spots, Try scaling the whole scene smaller. That way it uses less photons and can give you more flexability with the radiosity settings. Though a kool feature request would be to have a higher limit on the amount of photons. Photoman Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted July 10, 2009 Hash Fellow Share Posted July 10, 2009 What were you not able to get with non-radiosity rendering? Maybe there's some other solution. Quote Link to comment Share on other sites More sharing options...
Fuchur Posted July 10, 2009 Author Share Posted July 10, 2009 What were you not able to get with non-radiosity rendering? Maybe there's some other solution. I think it is hard to get an authentic look of glass without a very well lightening... I tried AO and some other things but I could get the lightening... Radiosity is just more authentic, including the light coming from the surroundin areas, near by geometry, the brighter parts where a geometry is near another one and the photons are reflecting several times and getting caught there... it just looks smoother and more diffuse than other stuff... AO didnt work out well... even with AO transparency activated it was much less bright. I tried to increase the ambiance-value of the paper behind the glass which was better, but still not what I was looking for... especially the thin edges of the glass (beveled) are not very pronounces by AO which makes the glass less visible... I tried setting up the specularity with additional lights but I couldnt get it to look right... I even think that the edges have to be less bright but darker to look right. I tried to scale the chor down and I get more possibilities with that, but I think the high Index of Refraction (Acryl has something like 1.5) is causing the problems behind the glass... Any idea what to do against that? the next thing I would try would be to render the paper flatshaded and the rest with radiosity... that may look okay. *Fuchur* Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted July 10, 2009 Hash Fellow Share Posted July 10, 2009 Your radiosity may be complicated by the fact that there are holes inthe set surrounding the object. Big ones on the sides. Aside from everything else, it's too many shadows. Use some specular only lights to highlight the bevels if you need to. Maybe what you really want is the "caustics" effect of the block of lucite. Quote Link to comment Share on other sites More sharing options...
Fuchur Posted July 10, 2009 Author Share Posted July 10, 2009 Your radiosity may be complicated by the fact that there are holes inthe set surrounding the object. Big ones on the sides. Aside from everything else, it's too many shadows. Use some specular only lights to highlight the bevels if you need to. Maybe what you really want is the "caustics" effect of the block of lucite. That one is nice too yes... but it is not only the caustics... it is just very smooth looking... I think I like the photon-look... a bit dirty but very lifelike... cant really say what it is... it just looks quite realistically... *Fuchur* Quote Link to comment Share on other sites More sharing options...
photoman Posted July 10, 2009 Share Posted July 10, 2009 Specularity and radiosity arent good frriends, If you used specularity make sure its very low (10%). Photoman Quote Link to comment Share on other sites More sharing options...
Hash Fellow robcat2075 Posted July 10, 2009 Hash Fellow Share Posted July 10, 2009 here are 3 more conventional renders without radiosity that use specular lights to highlight the edges acryl_block_specs.zip Quote Link to comment Share on other sites More sharing options...
Fuchur Posted July 13, 2009 Author Share Posted July 13, 2009 Thanks for your feedback... I finally descided to go the 3-point-road, which will work out okay, even so not as great as radiosity... I'll post a picture of it soon. It looks good enough. Thanks for your affords... *Fuchur* Quote Link to comment Share on other sites More sharing options...
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