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A long time ago, Jeroen kindly rendered this image for me in POVRay
http://miltontrainworks.com/MTW/images/MTWproductLine_1280x1024.jpg
But the source got lost. Now I need it much much larger so I'm trying to
recreate it. I am all the way there (all models positioned right, etc) except
for the lighting/shadows. Which may well be the hardest part!
I like how the shadows are, they are relatively light. I also like how the base
reflection is set up (i.e. there is none)
I've been trying a lot of different render settings and surface settings but I'm
either getting large muddy shadows, or I'm getting a surface that reflects the
models. Anyone have any clues on the best combination of surface materials (for
the white plane that everything sits on) and light source settings? I thought
maybe an area light was the way to go but it's not working well for me.
Here's my current surface settings...
texture {
pigment{ rgb <1,1,1> }
finish {
reflection 0
ambient 0.4
diffuse 0.5
roughness .01
}
}
Am I even on the right track there?
Thanks for any suggestions.
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In lugnet.cad.ray, Larry Pieniazek wrote:
> A long time ago, Jeroen kindly rendered this image for me in POVRay
>
> http://miltontrainworks.com/MTW/images/MTWproductLine_1280x1024.jpg
>
> But the source got lost. Now I need it much much larger so I'm trying to
> recreate it. I am all the way there (all models positioned right, etc) except
> for the lighting/shadows. Which may well be the hardest part!
>
> I like how the shadows are, they are relatively light. I also like how the base
> reflection is set up (i.e. there is none)
>
> I've been trying a lot of different render settings and surface settings but I'm
> either getting large muddy shadows, or I'm getting a surface that reflects the
> models. Anyone have any clues on the best combination of surface materials (for
> the white plane that everything sits on) and light source settings? I thought
> maybe an area light was the way to go but it's not working well for me.
>
> Here's my current surface settings...
>
> texture {
> pigment{ rgb <1,1,1> }
> finish {
> reflection 0
> ambient 0.4
> diffuse 0.5
> roughness .01
> }
> }
>
> Am I even on the right track there?
>
> Thanks for any suggestions.
Hi Larry,
I'm not much of a POV expert, but it looks to me like Jeroen used a single
light source (I only see one shadow per model). I'd guess the light source is
very far away (to simulate sunlight) because all the shadows cast proportionate
lengths.
To soften the shadows I'd think you would want to increase ambient and
diminish diffuse. The affect of diffuse depends on the angle of the light
hitting the surface, ambient is not. If you have control over ambient light
color I'd guess you want it white.
I'd practice on the lighting/background on a small model until you get what
you want but you're very smart, so you probably are already doing that. It
might also be faster to render each model separately, and then composite them
together into your final image.
Kevin
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It looks to me like each model / row of models was rendered in POV-Ray
individually and then PhotoShopped together. Probably removed any reflections
when combined on to one image.
Scott
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Kevin L. Clague wrote:
> I'm not much of a POV expert, but it looks to me like Jeroen used a
> single light source (I only see one shadow per model).
You can use many lights, and still have a single shadow by making all lights
but one 'shadowless' (a modifier to the POV light description). I often put
a (not too bright) shadowless light at the same position as the camera, to
make sure there's at least *some* light into all the cavities you can see.
--
Anders Isaksson
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In lugnet.cad.ray, Scott Wardlaw wrote:
> It looks to me like each model / row of models was rendered in POV-Ray
> individually and then PhotoShopped together. Probably removed any reflections
> when combined on to one image.
>
> Scott
I'm 99++% certain that's not the case, given the input data Jeroen was able to
recover for me. I think removing reflections would be a lot of work, better to
change the properties of the surface to get them not to happen.
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In lugnet.cad.ray, Larry Pieniazek wrote:
> A long time ago, Jeroen kindly rendered this image for me in POVRay
>
> http://miltontrainworks.com/MTW/images/MTWproductLine_1280x1024.jpg
>
> But the source got lost. Now I need it much much larger so I'm trying to
> recreate it. I am all the way there (all models positioned right, etc) except
> for the lighting/shadows. Which may well be the hardest part!
>
> I like how the shadows are, they are relatively light. I also like how the base
> reflection is set up (i.e. there is none)
>
> I've been trying a lot of different render settings and surface settings but I'm
> either getting large muddy shadows, or I'm getting a surface that reflects the
> models. Anyone have any clues on the best combination of surface materials (for
> the white plane that everything sits on) and light source settings? I thought
> maybe an area light was the way to go but it's not working well for me.
>
> Here's my current surface settings...
>
> texture {
> pigment{ rgb <1,1,1> }
> finish {
> reflection 0
> ambient 0.4
> diffuse 0.5
> roughness .01
> }
> }
>
> Am I even on the right track there?
>
> Thanks for any suggestions.
Looking at the lighting, I'm pretty sure he used radiosity and prolly his
FastRad library. I might still have a copy lemme poke around.
-Orion
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In lugnet.cad.ray, Kevin L. Clague wrote:
> I'm not much of a POV expert, but it looks to me like Jeroen used a single
> light source (I only see one shadow per model). I'd guess the light
> source is very far away (to simulate sunlight) because all the shadows
> cast proportionate lengths.
I am considering using parallel instead of a light source that's very far
away...
I don't think Jeroen used "parallel" for his source(s) because the shadow angles
are steeper in the foreground. (this will be less pronounced with light sources
farther away but to completely eliminate it you'd have to use parallel
lights...)
Since the camera is orthographic it sort of does make sense to use parallel
>
> To soften the shadows I'd think you would want to increase ambient and
> diminish diffuse. The affect of diffuse depends on the angle of the light
> hitting the surface, ambient is not. If you have control over ambient light
> color I'd guess you want it white.
I think the ambient light color is the color of the surface, which in this case
is white already. I am confused about what diffuse does, I guess... I thought it
was a way to kill reflections (and reflection 0 is another)... with just a
default surface I was getting a lot of reflections of the image elements which I
don't want. (one model reflecting off another is fine but I want the background
to be completely matte)
>
> I'd practice on the lighting/background on a small model until you get what
> you want but you're very smart, so you probably are already doing that. It
> might also be faster to render each model separately, and then composite them
> together into your final image.
I don't think I want to composite, it seems likely to be error prone. As well as
a lot of work :)
For my tests, to improve speed, I am using most of the model removed but enough
remains that I can check things like shadow angles and lighting amounts. It
renders fast enough for me I guess. (Facebooking in another window passes the
time)
Once I get the final settings right I am going to render it on a machine I can
just leave running all week while I'm away.
Note: ultimately I would actually like my shadows to be slightly fuzzy, not
sharp edged, so I am guessing maybe I should be using an area light placed a
very long way away. And I guess to get the shadows to be light I should place
some low intensity shadowless lights at other positions?
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In lugnet.cad.ray, Anders Isaksson wrote:
> Kevin L. Clague wrote:
> > I'm not much of a POV expert, but it looks to me like Jeroen used a
> > single light source (I only see one shadow per model).
>
> You can use many lights, and still have a single shadow by making all lights
> but one 'shadowless' (a modifier to the POV light description). I often put
> a (not too bright) shadowless light at the same position as the camera, to
> make sure there's at least *some* light into all the cavities you can see.
How bright is "not too bright"? These lights don't obey the r**2 law like real lights do, right? I noticed that if I have several rgb<1,1,1> lights the scene seems "overilluminated" Do you use .5 or so for the not too bright ones?
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Larry Pieniazek wrote:
> How bright is "not too bright"? These lights don't obey the r**2 law
> like real lights do, right? I noticed that if I have several
> rgb<1,1,1> lights the scene seems "overilluminated" Do you use .5
> or so for the not too bright ones?
Actually, the sum of *all* your lights should not be too much over <1,1,1>
as some parts of the image may be saturated. I usually use 0.5-0.7 for the
*brightest* light, and 0.1-0.3 for filler lights.
Remember it's easy to modify light intensity by placing the multiplier
before the 'light vector', like
0.2*<1, 1, 1>
this makes it easier to test different values, especially if you are
experimenting with colored lights.
--
Anders Isaksson
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Larry Pieniazek wrote:
> I think the ambient light color is the color of the surface, which in
> this case is white already. I am confused about what diffuse does,
If I understand it correctly, 'ambient' is what you see if all lights are
off. I usually turn this down very low (zero). 'Diffuse' is reflected light
from
other surfaces, you'd want quite a lot of that.
> with just a default surface I was getting a lot of reflections
Yes, I think the default 'reflection' value is too high in many cases.
> Note: ultimately I would actually like my shadows to be slightly
> fuzzy, not sharp edged, so I am guessing maybe I should be using an
> area light placed a very long way away.
I'm still using the old POVRay 3.5 where the 'experimental radiosity' is
*very*
usable for getting life like renderings (at the cost of loooong rendering
times). I belive newer versions use other means to achieve the same thing
('media'?).
I'm still very proud of this render:
http://www.brickshelf.com/gallery/anders-isak/IdeaBookInspiration/playtable002.jpg
The general settings for that render is:
#declare AMB = 0;
#declare DIF = 0.8;
global_settings {
assumed_gamma 1.2
ambient_light 0
max_trace_level 25
adc_bailout 1/150
radiosity {
pretrace_start 0.08
pretrace_end 0.01
count 300
error_bound 0.1
recursion_limit 1
}
}
and *no* light sources except for the sky sphere
sky_sphere {
pigment {
gradient -y //weird sky vector...
color_map {
[0.5 rgb 1.25]
[1 rgb <.5,.7,1>*1.1]
}
}
}
(Just let me know if you want the full POV source for it)
> And I guess to get the shadows to be light I should place some low
> intensity shadowless
> lights at other positions?
Straight above (but far off) would be a candidate for this. And as said
above, with 'radiosity' no lights at all are needed.
Anders Isaksson
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In lugnet.cad.ray, Anders Isaksson wrote:
> (Just let me know if you want the full POV source for it)
Hi Anders! I sent a note requesting it to the address shown in your post, is it
still correct? Mine is, so you can use that one to send it. I really like the
way that image looks (as well as the next one in the Brickshelf gallery) so
would be pleased to get the source for both.
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Larry Pieniazek wrote:
> In lugnet.cad.ray, Anders Isaksson wrote:
>
> > (Just let me know if you want the full POV source for it)
>
> Hi Anders! I sent a note requesting it to the address shown in your
> post, is it still correct? Mine is, so you can use that one to send
> it. I really like the way that image looks (as well as the next one
> in the Brickshelf gallery) so would be pleased to get the source for
> both.
Received and replied with a zip of the .pov file and accompanying images.
The settings for the brighter render is probably in the out-commented light
settings in the .pov file (and without radiosity) - I don't know for sure, I
fiddled so much back and forth to find good lighting, and then I found
radiosity...
--
Anders Isaksson
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In lugnet.cad.ray, Larry Pieniazek wrote:
> A long time ago, Jeroen kindly rendered this image for me in POVRay
>
> http://miltontrainworks.com/MTW/images/MTWproductLine_1280x1024.jpg
>
> But the source got lost. Now I need it much much larger so I'm trying to
> recreate it. I am all the way there (all models positioned right, etc) except
> for the lighting/shadows. Which may well be the hardest part!
--snip--
> Am I even on the right track there?
>
> Thanks for any suggestions.
To take a stab at it:
* The light is very high. You'll have to tweak its angle.
* If you use an area_light you'll probably get the soft shadow edges
* Reflection is turned off or very low
* The ground has a fairly high ambience, probably about amb=0.8 dif=0.2
* There is a sky sphere
* The camera angle is small
Convert in LDview for better colours.
Tim
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In lugnet.cad.ray, Timothy Gould wrote:
> To take a stab at it:
> * The light is very high. You'll have to tweak its angle.
> * If you use an area_light you'll probably get the soft shadow edges
> * Reflection is turned off or very low
> * The ground has a fairly high ambience, probably about amb=0.8 dif=0.2
> * There is a sky sphere
> * The camera angle is small
>
> Convert in LDview for better colours.
Thanks for the tips... I used LDView to conver, and got a render that's much
closer to the original. However I've got one niggling difference that's bugging
me. The transparent colors seem "lighter" somehow, meaning that the interiors of
things you see through them are lighter than the original colors, rather than
darker, as in the original rendering. I tried playing with the filter, turning
the filter up from the LDView inserted default of .85 helped some, but not
enough. I'm pretty sure I'm using the same transparent colors.
Also LDView had some issues with converting the sticker (the Skyline logo) that
I had no idea how to fix, so I just copied an old logo in from a previous pov
file that L3P converted and that worked.
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Larry Pieniazek wrote:
> However I've got one niggling difference that's bugging me.
> The transparent colors seem "lighter" somehow, meaning that
> the interiors of things you see through them are lighter
> than the original colors, rather than darker, as in the
> original rendering.
Could be an effect of the 'ambient' value for the transparent colors. If you
look at the pov file I sent you, you can see that I have used the following
for color47:
#declare Color47 = #if (version >= 3.1) material { #end texture {
pigment { rgb <1,1,0.99> #if (QUAL > 1) filter 0.65 #end }
finish { ambient 0.65*AMB diffuse 0.65*DIF }
#if (QUAL > 1)
finish { phong 0.5 phong_size 40 reflection 0.2 }
#if (version >= 3.1) #else finish { refraction 1 ior 1.25 } #end
#if (BUMPS) normal { BUMPNORMAL } #end
#end
} #if (version >= 3.1) #if (QUAL > 1) interior { ior 1.25 } #end } #end
I don't know how much of that is original, and how much is my
modifications...
--
Anders Isaksson
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On 6/2/2011 3:33 PM, Orion Pobursky wrote:
> Looking at the lighting, I'm pretty sure he used radiosity and prolly his
> FastRad library. I might still have a copy lemme poke around.
>
> -Orion
FastRad is a good choice for this scene. I would also use a parallel
camera and lights.
Mike
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In lugnet.cad.ray, Michael Horvath wrote:
> On 6/2/2011 3:33 PM, Orion Pobursky wrote:
> > Looking at the lighting, I'm pretty sure he used radiosity and prolly his
> > FastRad library. I might still have a copy lemme poke around.
> >
> > -Orion
>
> FastRad is a good choice for this scene. I would also use a parallel
> camera and lights.
I am using an orthographic camera because I don't want perspective at all. I
didn't try parallel lights. (there are such? or do you mean area?) That may be
what I need to correct the shading differences.
One thing I'm still chasing is that I can't get the windows to have the "right"
transparency... either they are too light and it looks like the interiors are
"glowing" or if I turn the colors or transparency down, things get too gray. I'm
trying to get the same transparency as in the image I'm trying to mimic.
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On 6/22/2011 9:33 AM, Larry Pieniazek wrote:
> I am using an orthographic camera because I don't want perspective at all. I
> didn't try parallel lights. (there are such? or do you mean area?) That may be
> what I need to correct the shading differences.
>
> One thing I'm still chasing is that I can't get the windows to have the "right"
> transparency... either they are too light and it looks like the interiors are
> "glowing" or if I turn the colors or transparency down, things get too gray. I'm
> trying to get the same transparency as in the image I'm trying to mimic.
Yes, there are parallel lights that work just like orthographic cameras.
Check the docs. This way you will get uniform lighting on every object
in the scene.
Mike
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