Well it's been a few weeks and I'm back at school again so I don't have
as much time, but I recently finished building my new 800Mhz super
computer:-) Well my dad helped with about 1/2 the money hehe. So I
decided to introduce this new machine to its first render. This render
is of a real alcove in my house, except for the vase, just a few feet
from where I'm sitting now in my computer room. It's not quit finished
yet, though I rather like the results so far. This is rendered in
regular Pov with the radiosity settings bellow. When I export the scene
from Moray and try to use MegaPov radiosity however, it washes all the
shadows out. Instead of the nice dark shadows you see in the corner of
the alcove I get a uniform dark yellow which destroys all sense of depth
in the alcove. Does anyone know how I might get similar results to this
render using MegaPov radiosity? I did not play with any of the settings
in MegaPov just used radiosity{}. A dim light out the window and back a
bit provides most of the light, but I also have a plane 100 units up
with ambient 1. I also tried to set the ambient light level in MegaPov
down to 0 when using radiosity but that just resulted in a very dark,
almost black image. The room itself is a large box cut by a slightly
smaller box, the camera is inside this, the only hole letting light in
from the plane and point light is the hole for the window.

Here are the settings I used to render this image in regular Pov.

global_settings {
  adc_bailout 0.003922
  ambient_light <1.0,1.0,1.0>
  assumed_gamma 1.9
  hf_gray_16 off
  irid_wavelength <0.247059,0.176471,0.137255>
  max_intersections 64
  max_trace_level 10
  number_of_waves 10
  radiosity {
    brightness        3.3
    count        200
    distance_maximum 0.0
    error_bound      1.0
    gray_threshold   0.5
    low_error_factor 0.8
    minimum_reuse    0.015
    nearest_count    6
    recursion_limit  2
  }
}

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Attachments:
Download 'alcove.jpg' (59 KB)

Preview of image 'alcove.jpg'

Thomas Lake wrote:
> 
[...]
> 
> Here are the settings I used to render this image in regular Pov.
> 
> global_settings {
>   adc_bailout 0.003922
>   ambient_light <1.0,1.0,1.0>
>   assumed_gamma 1.9
>   hf_gray_16 off
>   irid_wavelength <0.247059,0.176471,0.137255>
>   max_intersections 64
>   max_trace_level 10
>   number_of_waves 10
>   radiosity {
>     brightness        3.3
>     count        200
>     distance_maximum 0.0
>     error_bound      1.0
>     gray_threshold   0.5
>     low_error_factor 0.8
>     minimum_reuse    0.015
>     nearest_count    6
>     recursion_limit  2
>   }
> }
> 

With megapov you should set brightness to 1.0 in nearly all cases, maybe
decrease error_bound and recursion_limit.  You could have to change the
texture's finishes too.

Your scene looks quite good, but the sunny parts should be much brighter.

Christoph

--
Christoph Hormann <chr### [at] gmxde>
Homepage: http://www.schunter.etc.tu-bs.de/~chris/

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Wow... that's a very nice image!

--
- Doug Eichenberg
  http://www.getinfo.net/douge
  dou### [at] nlsnet

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Very nice image...I like the mood it evokes. Love the blinds.

---Oldstench---
Avoid herd mentality.

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"Thomas Lake" <tla### [at] homecom> wrote...
> I did not play with any of the settings
> in MegaPov just used radiosity{}.

For your scene, you'll first probably have to increase the default count,
decrease the pretrace_end, and decrease the error_bound.

> A dim light out the window and back a
> bit provides most of the light, but I also have a plane 100 units up
> with ambient 1. I also tried to set the ambient light level in MegaPov
> down to 0 when using radiosity but that just resulted in a very dark,
> almost black image.

The reason is that when you did this, your plane with an ambient 1 turned
black (because the ambient_light of zero cancels out ALL ambient light in
the whole scene).  You will want to adjust the diffuse and ambient for each
object.  POV 3.1 uses the ambient value to determine brightness when
computing radiosity, but MegaPov uses diffuse.

-Nathan

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> in the alcove. Does anyone know how I might get similar results to this
> render using MegaPov radiosity? I did not play with any of the settings

I don't know, but thanks for the inspiration!

Grim

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