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26 Nov 2024 03:25:29 EST (-0500)
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From: The Pseudonym
Subject: Tips for Realism
Date: 14 Jan 2012 18:15:01
Message: <web.4f120b4ec797d80078d1c58b0@news.povray.org>
hi guys any tips on how to make this model look realistic? ive been tinkering
with old Moray for materials and i always come up with render thats either too
dark or too bright, and now this looks too cartoonish.

http://i1192.photobucket.com/albums/aa340/triodetube/2-1.jpg

http://i1192.photobucket.com/albums/aa340/triodetube/1-1.jpg

http://i1192.photobucket.com/albums/aa340/triodetube/mx-8body.jpg

thank you for your help.


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From: Christian Froeschlin
Subject: Re: Tips for Realism
Date: 14 Jan 2012 23:07:55
Message: <4f12511b@news.povray.org>
The Pseudonym wrote:

> hi guys any tips on how to make this model look realistic?

Try using

- radiosity for more realistic lighting
- a HDRI environment for realistic reflections (of course,
   textures reflectivities must also be checked)
- area lights for soft shadows.

Some of the hard edges on the model may contribute to a cartoony
or artificial look as well. Unfortunately there is no cure for that
except modelling rounded / bevelled edges.

Also, the tires could be a little darker, I think.


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From: Alain
Subject: Re: Tips for Realism
Date: 15 Jan 2012 16:13:54
Message: <4f134192@news.povray.org>

> hi guys any tips on how to make this model look realistic? ive been tinkering
> with old Moray for materials and i always come up with render thats either too
> dark or too bright, and now this looks too cartoonish.
>
> http://i1192.photobucket.com/albums/aa340/triodetube/2-1.jpg
>
> http://i1192.photobucket.com/albums/aa340/triodetube/1-1.jpg
>
> http://i1192.photobucket.com/albums/aa340/triodetube/mx-8body.jpg
>
> thank you for your help.
>
>

Work on your lighting and use radiosity. This works beter when you have 
some environment other than a plain white ground and background.

Using area_light does help.
Don't use multiple lights with the same intensity. Use one main light 
and some secondary or auxiliary dim lights.
Optionaly, use coloured secondary lights.

As it is a military vehicle, there are not a lot of reflective surfaces, 
but there are some. Using some HDR environment can do a lot to add 
realism. Here, you need some outdoors light probe.

The tires should be somewhat darker with some shinyness if new.
Somewhat used tires have mate, grayish flanks and darker treads.

Some broad and subtle highlights can be welcome. No flat paint is totaly 
flat, it always gives some weak highlights. Try adding something like:
specular 0.02 roughness 0.1

Alain


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From: clipka
Subject: Re: Tips for Realism
Date: 15 Jan 2012 17:28:47
Message: <4f13531f@news.povray.org>
Am 15.01.2012 00:10, schrieb The Pseudonym:
> hi guys any tips on how to make this model look realistic? ive been tinkering
> with old Moray for materials and i always come up with render thats either too
> dark or too bright, and now this looks too cartoonish.

 From my experience, Radiosity is /the/ one most essential thing to use 
for a realistic look - it makes one hell of a difference.

If you have any notable reflecting surfaces in your image (e.g. glass), 
second most essential thing is to give them something to reflect. It 
often doesn't even matter /what/ - a HDR light probe is a good idea 
there if you don't care to model a detailed environment for your item to 
live in.

At third place I'd rank area lights. No light source comes even close to 
a perfect point, even the sun isn't (it's far away, but also pretty 
large), and every observer unconciously "knows" it.

If you have any lights nearby, make sure they use realistic fading. 
That's a fade_power of 2, and a fade_distance something around the 
actual size of the light source. Don't use fade_distance to control the 
brightness - you have the light source color for that, which you can 
simply multiply by a scalar factor (expect to need surprisingly large 
values for that).

Which brings us to another important topic: Do get your gamma homework 
done right! (I wouldn't be surprised if this was the reason why you were 
struggling with the brightness.) I strongly suggest using POV-Ray 3.7 
(RC3), which is designed to handle gamma properly out of the box 
(provided you use #version 3.7 and assumed_gamma 1.0). POV-Ray 3.6 may 
need manual preprocessing of texture images to get it right.

Some slight focal blur may also do some good, especially for objects 
that are supposed to look small. A good aperture size is about whatever 
0.5 cm would be in POV-Ray units. Even if your object is large, you can 
add something in the foreground to get some good effect from the focal blur.

Apropos blur: If you have any surfaces that are neither perfectly dull 
nor perfectly shiny, you should consider using blurred reflections 
(which can be achieved in POV-Ray e.g. via the so-called "micronormals" 
approach). Be careful to balance them well with highlights.

(BTW, what people usually don't realize is that highlight intensity is 
/not/ necessarily in the same range as reflection brightness. For very 
tight highlights (which is what you should use to complement non-blurred 
reflections) it should be set surprisingly high. There's a formula I 
have somewhere to realistically relate reflection to highlight intensity 
depending on roughness and phong_size, respectively.)


Another thing often underestimated is beveling of edges. It's a hell lot 
of extra work, whether you use a mesh model or CSG, but it can make or 
break an image. Adding one flat extra facet at each corner may suffice, 
but for best effects use rounded edges. (Did I mention that it's a hell 
lot of work?)

Speaking of edges, so-called "proximity pattern" macros are good for 
adding rust or dirt to crevices, or giving edges a worn look, all of 
which adds to the credibility of the image. They /might/ also help 
faking beveled edges, though I've never seen anyone try yet; a simple 
moderate brightening of the texture close to the edge could do the trick.


(As an added note, if you're rendering small objects, or materials with 
notable translucency, subsurface scattering can make some difference. 
It's still experimental in POV-Ray 3.7 though, and this particular model 
won't need it anyway.)


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From: stbenge
Subject: Re: Tips for Realism
Date: 15 Jan 2012 20:26:59
Message: <4f137ce3$1@news.povray.org>
On 1/15/2012 2:28 PM, clipka wrote:
> Speaking of edges, so-called "proximity pattern" macros are good for
> adding rust or dirt to crevices, or giving edges a worn look, all of
> which adds to the credibility of the image. They /might/ also help
> faking beveled edges, though I've never seen anyone try yet; a simple
> moderate brightening of the texture close to the edge could do the trick.

You /can/ use a proximity pattern to bevel edges, and it works 
reasonably well. You just use it in a surface normal and give it a 
negative strength. The accuracy needs to be set to about 0.5-2.0 times 
the size of the proximity pattern.

I posted an image regarding this a while back, but I can't find it now :(


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From: The Pseudonym
Subject: Re: Tips for Realism
Date: 16 Jan 2012 19:45:01
Message: <web.4f14c35c21cc71bc716789a00@news.povray.org>
thanks for the detailed advices guys. i am saving this page on my hard-drive
cause im usually offline. so first thing i will do is smooth out the edges. then
create the jungle like environment and experiment with lights to have a
realistic reflection, i will blacken the tires too, and put muds in it. :)


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