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Help for a begginer

Posted: Thu Feb 03, 2011 10:33 pm
by elDiego
hi i'm new to indigo render, happy so far but for some reason my exterior renders look really nice and sharp but not the interiors, they look pixelated even if i have render both the same amount of time.
anyone can help out on this? would be much apreciate it.
here are examples so you guys can see what i mean. I wish all images would look like t1. Thanks

Re: Help for a begginer

Posted: Fri Feb 04, 2011 12:04 am
by Zom-B
Hi Diego, welcome to Indigo :)

for interiors make sure to use Exit Portals to speed up rendering a lot (see manual for detailed explenation how to set them up).

Your bluish interring also seems to have glass windows, in this case try MLT+BiDir over pure PT for a better result!
Also something to try out would be the new Glass Acceleration feature (for BiDir mode)
http://www.indigorenderer.com/forum/vie ... =1&t=10245

Your orange tinted Image seems to have some strange lightsource, no idea why it is rendering that slow.
double check your light emitter mesh to have normals facing outside and also try to use lower poly meshes as emitter to speed things up :)

Re: Help for a begginer

Posted: Fri Feb 04, 2011 11:45 pm
by elDiego
THANKS! I'm gonna try doing what you just said. I'll let you know if I had better results.

Re: Help for a begginer

Posted: Sat Feb 05, 2011 2:06 am
by Reinuvader
Thing is that interior renderings need almost always more rendering time. Less light are coming in, and we need more samples to lit the scene.

OK, this maybe is bullshit what I just said, but thats what I think :)

Exit portal doesn't suit your images, because you want to see other geometry through windows (wall of your building in first image). Exit portal is good only if you position your camera so you don't see anything except sky. If you want see through windows other buildings/nature or other kind of background, you should consider adding them in Photoshop.

As Zom-B said, you have strange lightsource in night scene. Probably Glossy Transparent or something worse. In this image I would use simple white diffuse material which emits light.

I am not sure what 3D software you use, but if you use Sketchup, then in your first image (bluish interior) it seems to me you have white default material. You should change it as soon as possible, because it looks sometimes like an emitter too. I have made my Sketchup default startup scene to have only one diffuse material which is "white plaster" and I apply this to every object if I don't know what final material should be.

And small final tip: Never use 100% white or black. Black rubber tires are never 100% black and white paper or plastic is never 100% white. My "white plaster" is for example 90% white, and maybe even this is too much.

Re: Help for a begginer

Posted: Sat Feb 05, 2011 2:57 am
by Headroom
Reinuvader wrote:Thing is that interior renderings need almost always more rendering time. Less light are coming in, and we need more samples to lit the scene.

OK, this maybe is bullshit what I just said, but thats what I think :)
Nope. You're correct. Also in interior scenes there is a lot more of indirect light.
Reinuvader wrote: And small final tip: Never use 100% white or black. Black rubber tires are never 100% black and white paper or plastic is never 100% white. My "white plaster" is for example 90% white, and maybe even this is too much.
Correct as well and 90% is too much. No real world measured reflectance is over 80% or 205 in RGB. This also helps reducing render times as light does not have to "bounce around" so much.

Re: Help for a begginer

Posted: Sat Feb 05, 2011 3:38 am
by Reinuvader
Oh, good to know. I didn't know this affects rendering speed. This makes me think, that maybe exporters should have slider or button to reduce all material and texture levels to fit in measured value.

Re: Help for a begginer

Posted: Sat Feb 05, 2011 5:03 am
by elDiego
true i never thought about the white being too white, thanks

Re: Help for a begginer

Posted: Sat Feb 05, 2011 5:10 am
by Zom-B
Reinuvader wrote:Oh, good to know. I didn't know this affects rendering speed. This makes me think, that maybe exporters should have slider or button to reduce all material and texture levels to fit in measured value.
This is actually nothing unknown to mankind :D
C4D for example hast all material set to 204 by default...

Here are some (old) numbers:
http://www.indigorenderer.com/forum/vie ... 251#p85251

Re: Help for a begginer

Posted: Sat Feb 05, 2011 5:28 am
by Reinuvader
OK, but do you know about the lowest/darkest values? what is darkest measured surface. Charcoal? How much I have to lighten it up? As I understand, it means I have to change my textures output values in Photoshop.

Re: Help for a begginer

Posted: Sat Feb 05, 2011 5:42 am
by Zom-B
actually no need to do this in PS, Indigo has some texture parameters A, B and C.
Afaik setting B to 0.8 results in the same way.
Also Tinted materials/Textures shouldn't have single colors over 204 for optimized result & performance,
but remember that simply setting full texture to 80% also darkens the fine colors... in some situation this isn't wanted.

To dark values aren't slowing anything down, but reduce (albedo) reflection of light to zero with pure black.
Your charcoal should have values of 5 to 15 in RGB, whatever looks best. Since most materials are phong based actually (with low IOR and exponent) you have here some reflection that isn't based on the albedo color too...

** EDIT **
ah, ok... you actually clamp the values. is there something possible like this with ABC guys??