POV-Ray : Newsgroups : povray.general : QUESTION: Bump_Map not Effective? Server Time: 19 Oct 2017 10:52:51 GMT
  QUESTION: Bump_Map not Effective? (Message 5 to 14 of 14)  
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From: Thomas de Groot
Subject: Re: QUESTION: Bump_Map not Effective?
Date: 16 Jul 2017 10:58:49
Message: <596b46e9@news.povray.org>
On 16-7-2017 9:08, omniverse wrote:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> On 16-7-2017 1:41, Sven Littkowski wrote:
>>> I never actually used bump_maps before. Now I try to use one, but not
>>> seeing any effect. Can someone assist me?
>>>
>>> The scene contains a stratosphere helium balloon, and the bump_map
>>> should have created the typical balloon surface. However, I don't see
>>> the surface changed. Before posting any images, I show you the scene
>>> file. is there any error the way I do it?
>>>
>>> -------------------------------------------
>>
>> Same comments as Omniverse. I give you here an example from my
>> BeenThereDoneThat scene, the moon in the sky:
>>
>> #declare MoonMap =
>>     texture {
>>       pigment {
>>         image_map {
>>           png "PlanetMaps/MoonMap.png" gamma 1.0
>>           map_type 1
>>           once
>>           interpolate 2
>>         }
>>       }
>>       normal {
>>         bump_map {
>>           png "PlanetMaps/MoonBump.png"
>>           map_type 1
>>           once
>>           interpolate 2
>>         }
>>         bump_size 5.0
>>       }
>>       finish {
>>         diffuse albedo 0.9
>>       }
>>     }
>>
>> That is all that is needed. The bump_size is even rather high but works
>> best for this scene.
>>
>> Note that in order for the maps to be effective you need to add the
>> map_type parameter which seems to be missing in your code. 1 is for a
>> sphere. See docs for mor info on image_maps and bump_maps.
>>
>> --
>> Thomas
> 
> Definitely onto something there Thomas. I was looking at it again because I
> thought there was a reason for the default planar mapping, but I wondered if
> that could be a mistake for this particular thing.
> map_type 1 will wrap around the balloon shape spherically and not need
> translate, rotate or scale.
> 
> But the main thing I was thinking about was to skip the image_map to get a
> better look at what the bump_map is doing. So to try that, Sven, you might want
> to look at it with only pigment { rgb 1 filter 0.5 } or similar. That way you
> can see the normal alone.
> 
> I realized my attempt using my own image file masked the appearance somehow.
> Probably something to do with the bump_map being like an illusion and not a real
> surface deformation for the visible image to paint onto. So using the plain
> pigment color it highlights the bump_map instead of masking it from view.
> At least that's my thought on this.
> 
> Bob
> 
> 
>

You are absolutely right. Best to test with a plain pigment, preferably 
a light one. ;-)


-- 
Thomas


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From: omniverse
Subject: Re: QUESTION: Bump_Map not Effective?
Date: 17 Jul 2017 06:00:06
Message: <web.596c51763b5fa6e29c5d6c810@news.povray.org>
Sven, I found some possible errors in other things you might not be aware of
yet. I was trying a remake of your scene file, just like I often do with SDL
shared by other people.

The top of the LowerBalloonShape was not differenced out completely, so unless
you intend a parachute hovering above the balloon you will need to increase the
cylinder height from 175.001 to MyRadius+0.001 in the y direction.

The position lights are embedded into the surface of the cylinder ends, and
moving each light_source from the current 10 to maybe 10.25 (x direction) should
make those visible. I was not seeing them before changing that.

I didn't continue with your bump_map and instead used:

 normal {radial frequency 24 bump_size 6} // wraps around y axis

for both the outside and inside textures.
And just a pigment {rgb 1 transmit 0.2}, although I'm curious what your balloon
bump_map image is and if that was too low in contrast or some other reason for
not showing obvious surface features.

Bob


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From: omniverse
Subject: Re: QUESTION: Bump_Map not Effective?
Date: 17 Jul 2017 15:50:01
Message: <web.596cdc593b5fa6e29c5d6c810@news.povray.org>
"omniverse" <omn### [at] charternet> wrote:
>
> I didn't continue with your bump_map and instead used:
>
>  normal {radial frequency 24 bump_size 6} // wraps around y axis

There should have been a scallop_wave in there too, sorry. Not suggesting you
change your way of doing things, I was just telling what I did.

Bob


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From: Sven Littkowski
Subject: Re: QUESTION: Bump_Map not Effective?
Date: 23 Jul 2017 22:15:26
Message: <59751ffe$1@news.povray.org>
On 17.07.2017 11:48, omniverse wrote:
> "omniverse" <omn### [at] charternet> wrote:
>>
>> I didn't continue with your bump_map and instead used:
>>
>>  normal {radial frequency 24 bump_size 6} // wraps around y axis
> 
> There should have been a scallop_wave in there too, sorry. Not suggesting
 you
> change your way of doing things, I was just telling what I did.
> 
> Bob
> 
> 
> 


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From: Sven Littkowski
Subject: Re: QUESTION: Bump_Map not Effective?
Date: 23 Jul 2017 22:22:07
Message: <5975218f@news.povray.org>
On 17.07.2017 11:48, omniverse wrote:
> "omniverse" <omn### [at] charternet> wrote:
>>
>> I didn't continue with your bump_map and instead used:
>>
>>  normal {radial frequency 24 bump_size 6} // wraps around y axis
> 
> There should have been a scallop_wave in there too, sorry. Not suggesting you
> change your way of doing things, I was just telling what I did.
> 
> Bob
> 
> 
> 
Thanks to you all. :-)
And sorry for my absence, I was not at home.

I think, it might be a good idea to attach the bump_map file. Just for
size reasons, it is now a JPG, but you can put it back to a PNG file.

I also added the once keyword and the map_type. Still, no change.

Will apply the other correctional changes as advised. but please see my
bump_map file and check out. Thanks.


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Attachments:
Download 'space - launcher - balloon - type 001 - moon runnings - balloon bumpmap.jpg' (436 KB)

Preview of image 'space - launcher - balloon - type 001 - moon runnings - balloon bumpmap.jpg'
space - launcher - balloon - type 001 - moon runnings - balloon bumpmap.jpg


 

From: omniverse
Subject: Re: QUESTION: Bump_Map not Effective?
Date: 24 Jul 2017 05:55:00
Message: <web.59758b8e3b5fa6e29c5d6c810@news.povray.org>
Sven Littkowski <I### [at] SvenLittkowskiname> wrote:

I replied to your message at povray.binaries.images with a changed SDL text and
the image file after I enhanced it for contrast and smoothness (was grainy
before).
You should be able to see how the bumpiness looks from rendering that now.

I did some excercises in scaling to get it best way I could, as you might find
out when reading it.
Anyway, see what I wrote there and download the other image for it.

There's probably a better way, that just what I managed to do.

Bob


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From: clipka
Subject: Re: QUESTION: Bump_Map not Effective?
Date: 24 Jul 2017 16:53:50
Message: <5976261e$1@news.povray.org>
Am 24.07.2017 um 00:22 schrieb Sven Littkowski:

> I think, it might be a good idea to attach the bump_map file. Just for
> size reasons, it is now a JPG, but you can put it back to a PNG file.

That was a good idea indeed.

> I also added the once keyword and the map_type. Still, no change.
> 
> Will apply the other correctional changes as advised. but please see my
> bump_map file and check out. Thanks.

Your bump map is way oversized in terms of image dimensions. Or, more
precisely, in terms of image dimensions vs. dynamic range. As a
consequence you get color banding, which has the effect of
disintegrating the bumps into almost infinitesimally thin lines.

For a bump map, you want to make sure that the typical "slope" in your
image is /at least/ 1 "brightness step" per pixel.

There are several ways to improve your image in this respect:

(1) Significantly reduce the bump map's size in pixels.

(2) Re-create your bump map with more contrast, to make full use of the
bit depth provided by the image format.

(3) Re-create your bump map at a higher bit depth (e.g. 16 bits instead
of 8).


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From: Sven Littkowski
Subject: Re: QUESTION: Bump_Map not Effective?
Date: 24 Jul 2017 23:46:40
Message: <597686e0@news.povray.org>
Here's the updated bump image. I reduced its size, made it 16bit, and
increased the contrast between dark and bright areas. Still - no
success.   :-(

Another problem: The same thread exists inside the IMAGE section. I
posted there at first before making up my mind that it might be a
GENERAL topic. Now we have two identical threads. I think, we all should
just use THIS thread here, inside GENERAL.


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Attachments:
Download 'space - launcher - balloon - type 001 - moon runnings - balloon bumpmap.png' (314 KB)

Preview of image 'space - launcher - balloon - type 001 - moon runnings - balloon bumpmap.png'
space - launcher - balloon - type 001 - moon runnings - balloon bumpmap.png


 

From: clipka
Subject: Re: QUESTION: Bump_Map not Effective?
Date: 25 Jul 2017 05:15:34
Message: <5976d3f6$1@news.povray.org>
Am 25.07.2017 um 01:46 schrieb Sven Littkowski:
> Here's the updated bump image. I reduced its size, made it 16bit, and
> increased the contrast between dark and bright areas. Still - no
> success.   :-(
> 
> Another problem: The same thread exists inside the IMAGE section. I
> posted there at first before making up my mind that it might be a
> GENERAL topic. Now we have two identical threads. I think, we all should
> just use THIS thread here, inside GENERAL.

Since images will probably be sent back and forth,
`povray.binaries.image` is the more suitable location.

Posting attachments is generally discouraged, and actually impossible
from the web interface (http://news.povray.org), in all newsgroups
except those named `povray.binaries.*`.


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From: Sven Littkowski
Subject: Re: QUESTION: Bump_Map not Effective?
Date: 25 Jul 2017 05:56:24
Message: <5976dd88$1@news.povray.org>
On 25.07.2017 01:15, clipka wrote:
> Am 25.07.2017 um 01:46 schrieb Sven Littkowski:
>> Here's the updated bump image. I reduced its size, made it 16bit, and
>> increased the contrast between dark and bright areas. Still - no
>> success.   :-(
>>
>> Another problem: The same thread exists inside the IMAGE section. I
>> posted there at first before making up my mind that it might be a
>> GENERAL topic. Now we have two identical threads. I think, we all should

>> just use THIS thread here, inside GENERAL.
> 
> Since images will probably be sent back and forth,
> `povray.binaries.image` is the more suitable location.
> 
> Posting attachments is generally discouraged, and actually impossible
> from the web interface (http://news.povray.org), in all newsgroups
> except those named `povray.binaries.*`.
> 
Agreed. Okay, everyone please check the IMAGES version of this thread
from now on. Thanks. :-)

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