This is something that has been bothering me for some time. My scene files are
all very 'clinical', that is they are too perfect. For example, I have rendered
a scene with a paved street, a brick wall and a lamp post, but everything looks
perfectly 'clean'; the wall is perfectly straight, there is no dirt, no rubbish,
no anything other than what I have already mentioned. What do I have to do to
get natural looking scenes?

Also, in over a year of using POV-Ray, I have not progressed much beyond the
basic solid primitives, and blob has gone almost unused. Is there any kind of
maths I need to study, or do I need to use a modeler, or what?

If anyone could give me a hand with these questions, I would be much obliged.

D103

Post a reply to this message

> This is something that has been bothering me for some time. My scene files are
> all very 'clinical', that is they are too perfect. For example, I have rendered
> a scene with a paved street, a brick wall and a lamp post, but everything looks
> perfectly 'clean'; the wall is perfectly straight, there is no dirt, no rubbish,
> no anything other than what I have already mentioned. What do I have to do to
> get natural looking scenes?
>
> Also, in over a year of using POV-Ray, I have not progressed much beyond the
> basic solid primitives, and blob has gone almost unused. Is there any kind of
> maths I need to study, or do I need to use a modeler, or what?
>
> If anyone could give me a hand with these questions, I would be much obliged.
>
> D103
>
>
>

You can use some creative texturing to dirtyup your objects. Some 
gradient going from dirty to clean that you layer over the base onject's 
texture. You can also use some image_map.

For the rubish, you need to model and place it.

Replace your wall made from a single box by one made from a LOT of 
smaller boxes. Use one or some bricks made as meshes, mirror and rotate 
them around to make them look like there are many more models. There are 
some free modelers around that can help, or you can use some ready made 
ones. Look in the objects collection.

If you have a vast glass wall and it have some seams using texturing, 
adding some normal perturbation with the cells pattern scalled to match 
the details can be good. Just use a small bump_size. Nesting pattern can 
be fun.

Use light placement creatively, play with the shadows.
Use area_light. I recomend using the adaptive option and a relatively 
dence array. Start with adaptive 0 and increase the value if needed.

Place your camera artisticaly, apply a small amount of tilting, like 
less that 1 or 2 degrees.
Use a whide field of view, of a narrow one and the camera pulled back, 
and experiment with the various projection modes: spherical, omnimax, 
ultrawhideangle, fisheye,...
For play, apply some small normal to the camera.
Use focal blur, but not while desining the scene.

Use fog (now), or media (later).

Don't forget to also model the background, those far away scene 
elements. Also, don't forget to put something outside your field of 
view. It can cast some shadows, and can be essential if you have 
anything reflective.
It also enable you to move and orient the camera with more latitude/freedom.

Don't be afraid to experiment. Explore the primitives that you barely or 
did not already use. A bicubic_patch object can do a good job as some 
stray papers... Come back here if you have more questions.

Regarding maths, some trigonometry, mostly basic, can help.



Alain

Post a reply to this message

D103 <nomail@nomail> wrote:
> This is something that has been bothering me for some time. My scene files are
> all very 'clinical', that is they are too perfect. For example, I have rendered
> a scene with a paved street, a brick wall and a lamp post, but everything looks
> perfectly 'clean'; the wall is perfectly straight, there is no dirt, no rubbish,
> no anything other than what I have already mentioned. What do I have to do to
> get natural looking scenes?

  Texturing (especially proper selection of pigments and normals) helps.

http://warp.povusers.org/povtips/
http://wiki.povray.org/content/Documentation:Tutorial_Section_3.3#Slope_Map_Tutorial

-- 
                                                          - Warp

Post a reply to this message

Random numbers are your friend.

You can use random values to modify scale, translation, rotation, 
color_maps, isosurface values--anything with numbers in it can be "nudged."

You can use a macro with some randomness built into it to create 
multiple small objects like bricks or boards.  Call the macro from 
inside a loop to build walls and so forth.

For simple, basically rectangular shapes like bricks or building stones, 
try using code to build a simple mesh and then randomly nudge its 
individual points in a macro.  This works really well with a nice, bumpy 
texture, the kind that hides a multitude of sins.  ;)

--Sherry Shaw

-- 
#macro T(E,N)sphere{x,.4rotate z*E*60translate y*N pigment{wrinkles scale
.3}finish{ambient 1}}#end#local I=0;#while(I<5)T(I,1)T(1-I,-1)#local I=I+
1;#end camera{location-5*z}plane{z,37 pigment{granite color_map{[.7rgb 0]
[1rgb 1]}}finish{ambient 2}}//                                   TenMoons

Post a reply to this message

And to add to what others have said, follow these newsgroups, much of 
the blood, sweat, and tears around here is associated with just that 
problem.

Here's an simple exercise: how do I get my pigment texture to 
synchronize with my bump texture?

Post a reply to this message

Alain <aze### [at] qwertyorg> wrote:

> > This is something that has been bothering me for some time. My scene files are
> > all very 'clinical', that is they are too perfect. For example, I have rendered
> > a scene with a paved street, a brick wall and a lamp post, but everything looks
> > perfectly 'clean'; the wall is perfectly straight, there is no dirt, no rubbish,
> > no anything other than what I have already mentioned. What do I have to do to
> > get natural looking scenes?
> >
> > Also, in over a year of using POV-Ray, I have not progressed much beyond the
> > basic solid primitives, and blob has gone almost unused. Is there any kind of
> > maths I need to study, or do I need to use a modeler, or what?
> >
> > If anyone could give me a hand with these questions, I would be much obliged.
> >
> > D103
> >
> >
> >
>
> You can use some creative texturing to dirtyup your objects. Some
> gradient going from dirty to clean that you layer over the base onject's
> texture. You can also use some image_map.
>
> For the rubish, you need to model and place it.
>
> Replace your wall made from a single box by one made from a LOT of
> smaller boxes. Use one or some bricks made as meshes, mirror and rotate
> them around to make them look like there are many more models. There are
> some free modelers around that can help, or you can use some ready made
> ones. Look in the objects collection.
>
> If you have a vast glass wall and it have some seams using texturing,
> adding some normal perturbation with the cells pattern scalled to match
> the details can be good. Just use a small bump_size. Nesting pattern can
> be fun.
>
> Use light placement creatively, play with the shadows.
> Use area_light. I recomend using the adaptive option and a relatively
> dence array. Start with adaptive 0 and increase the value if needed.
>
> Place your camera artisticaly, apply a small amount of tilting, like
> less that 1 or 2 degrees.
> Use a whide field of view, of a narrow one and the camera pulled back,
> and experiment with the various projection modes: spherical, omnimax,
> ultrawhideangle, fisheye,...
> For play, apply some small normal to the camera.
> Use focal blur, but not while desining the scene.
>
> Use fog (now), or media (later).
>
> Don't forget to also model the background, those far away scene
> elements. Also, don't forget to put something outside your field of
> view. It can cast some shadows, and can be essential if you have
> anything reflective.
> It also enable you to move and orient the camera with more latitude/freedom.
>
> Don't be afraid to experiment. Explore the primitives that you barely or
> did not already use. A bicubic_patch object can do a good job as some
> stray papers... Come back here if you have more questions.
>
> Regarding maths, some trigonometry, mostly basic, can help.
>
>
>
> Alain

Thanks Alain,
I'm still experimenting with dirty textures, and I think I've got the rubbish
sorted out, but I'm still having problems with the brick wall. I started of
using the irregular bricks macro, but I couldn't simulate a difference in depth
between the bricks and the mortar using normals. I found a file in the objects
collection called meshrelief, and I tried using a box for the mortar and a
#while loop to place the bricks along it, but the results still looked very
flat.

As for the paved street, I replaced the brick texture with a crackle texture and
normal to go along with it, the results were satisfactory.

The lighting is solely provided by lampposts, as the scene is in the dark.

I have yet to fiddle with the camera settings, apart from focal blur, which I
have decided not to use, as all of the scene is fairly close up.

Media might be of some use, but I haven't got around to that either.

Thanks for the idea with bicubic patches, I feel that could become very useful.

When I mentioned maths, I was thinking more of functions, but in any case I
happen to have just finished trigonometry in my maths.

Warp <war### [at] tagpovrayorg> wrote:
>
> Texturing (especially proper selection of pigments and normals) helps.
>
> http://warp.povusers.org/povtips/
> http://wiki.povray.org/content/Documentation:Tutorial_Section_3.3#Slope_Map_Tutorial
>
> --
>                                                           - Warp

Thanks for the links, I found them quite helpful. One thing though, the floor
boards look as though they have been coated in plastic. I have come across this
before, is there a way to get polished looking wood without it looking plastic?


Sherry Shaw <ten### [at] aolcom> wrote:
> Random numbers are your friend.
>
> You can use random values to modify scale, translation, rotation,
> color_maps, isosurface values--anything with numbers in it can be "nudged."
>

I haven't got much experience with random numbers, but I'll do some
experimentation.

> You can use a macro with some randomness built into it to create
> multiple small objects like bricks or boards.  Call the macro from
> inside a loop to build walls and so forth.
>

As previously mentioned, I did use a macro in textures.inc to make my original
brick wall, I am at present trying others from the objects collection and other
sources.

> For simple, basically rectangular shapes like bricks or building stones,
> try using code to build a simple mesh and then randomly nudge its
> individual points in a macro.  This works really well with a nice, bumpy
> texture, the kind that hides a multitude of sins.  ;)

I did this using a file from the objects collection, the bricks looked ok, but
when I added mortar as mentioned above, the wall looked like one surface with a
colour map and a single normal.

>
> --Sherry Shaw
>
> --
> #macro T(E,N)sphere{x,.4rotate z*E*60translate y*N pigment{wrinkles scale
> .3}finish{ambient 1}}#end#local I=0;#while(I<5)T(I,1)T(1-I,-1)#local I=I+
> 1;#end camera{location-5*z}plane{z,37 pigment{granite color_map{[.7rgb 0]
> [1rgb 1]}}finish{ambient 2}}//                                   TenMoons


Jim Charter <jrc### [at] msncom> wrote:
> And to add to what others have said, follow these newsgroups, much of
> the blood, sweat, and tears around here is associated with just that
> problem.
>
> Here's an simple exercise: how do I get my pigment texture to
> synchronize with my bump texture?

I can do this fine by using the same pattern, but if the pigment is created
using a macro, like for the brick wall I mentioned earlier, I can't get the
normal to sync with the pigment, POV-Ray sends this message: Cannot layer over a
layered texture. Or something like that.

Thank you everyone for helping.

D103

Post a reply to this message

As regards the brick wall, I have gone for a simple box with a more complex
texture.

I have also made a piece of "paper" from a bicubic_patch, I have used rand for
the first time to wrinkle the paper and place it randomly with a while loop. It
took some time, but I have found rand really helpful.

For my light in the lamp I have used a frame. This is causing far too harsh
shadows, even with radiosity. I don't want to use an area light if possible, are
there any other options?

About the macros used to build bricks, how do they work? I have read the files
but don't really understand them. Also I keep reading posts where people say to
use macros to build a mesh, but I have no idea of how to do this.

D103

Post a reply to this message

Am 23.01.2011 03:20, schrieb D103:

> For my light in the lamp I have used a frame. This is causing far too harsh
> shadows, even with radiosity. I don't want to use an area light if possible, are
> there any other options?

Don't be afraid of area lights.

Post a reply to this message

> For my light in the lamp I have used a frame. This is causing far too 
harsh
 > shadows, even with radiosity. I don't want to use an area light if 
possible, are
 > there any other options?


Give the lamp shade no_shadow and use two spot lights (one up and one 
down) with soft edges that more or less match the shade. Also use a 
basic dim light source to simulate the light that filters through the shade.

But as clipka said, don't be afraid of area lights. Although this trick 
can help you avoid lots of area light calculations from the lamp shade, 
soft shadowing on all of your objects will look way better than hard 
shadows, and if you use 'adaptive' properly, it really won't hurt your 
render times that much.

Post a reply to this message

> As regards the brick wall, I have gone for a simple box with a more complex
> texture.
>
> I have also made a piece of "paper" from a bicubic_patch, I have used rand for
> the first time to wrinkle the paper and place it randomly with a while loop. It
> took some time, but I have found rand really helpful.
>
> For my light in the lamp I have used a frame. This is causing far too harsh
> shadows, even with radiosity. I don't want to use an area light if possible, are
> there any other options?
>
> About the macros used to build bricks, how do they work? I have read the files
> but don't really understand them. Also I keep reading posts where people say to
> use macros to build a mesh, but I have no idea of how to do this.
>
> D103
>
>

Why don't use area_light?

An area_light ,even with a high density, with the adaptive option can be 
relatively fast.

Try this, rather extreme, one:
light_source{<40, 80, -40> rgb 1 area_light 8*x, 8*z, 257, 257 adaptive 
0 circular orient}
No real need to use jitter with that density.

And compare it to the proposed one from the insert menu.

light_source {<0,0,0> color rgb 1.0
   area_light <8, 0, 0> <0, 0, 8> 4, 4
   jitter circular orient translate <40, 80, -40>
}

Both cover the same area.


Alain

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