Hi All

Don't really know where to put this...

I have been attempting to create realistic figures using image maps and
amongst the many problems I have encountered is adding specular to semi
transparent meshes.

What I need to do is add specular highlights to the opaque parts of the mesh
only.

Is this a reson for specular maps?

Any suggestions?

Mick

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Instead of using a color_map to define transparent and non-transparent areas
use a texture_map. Then for the transparent areas don't use specular in the
finish block.
Finish_maps would help a lot here.
--
Jonathan.

"Mick Hazelgrove" <mic### [at] mhazelgrovefsnetcouk> ha scritto nel messaggio
news:3be5330e@news.povray.org...
> Hi All
>
> Don't really know where to put this...
>
> I have been attempting to create realistic figures using image maps and
> amongst the many problems I have encountered is adding specular to semi
> transparent meshes.
>
> What I need to do is add specular highlights to the opaque parts of the
mesh
> only.
>
> Is this a reson for specular maps?
>
> Any suggestions?
>
> Mick
>
>

Post a reply to this message

"JRG" <jrg### [at] hotmailcom> wrote in message
news:3be53443@news.povray.org...
> Instead of using a color_map to define transparent and non-transparent
areas
> use a texture_map.

I'm using an image map with the transparent areas defined by the alpha
channal attached to the image map - so I can't really do this.

Mick

Post a reply to this message

Oops. Sorry.
Maybe you may try to use a greyscale version of your image_map as pattern
for a texture_map (and use your normal image_map inside every textures).

--
Jonathan.
"Mick Hazelgrove" <mic### [at] mhazelgrovefsnetcouk> ha scritto nel messaggio
news:3be536c2@news.povray.org...
>
> "JRG" <jrg### [at] hotmailcom> wrote in message
> news:3be53443@news.povray.org...
> > Instead of using a color_map to define transparent and non-transparent
> areas
> > use a texture_map.
>
> I'm using an image map with the transparent areas defined by the alpha
> channal attached to the image map - so I can't really do this.
>
> Mick
>
>
>

Post a reply to this message

> I'm using an image map with the transparent areas defined by the alpha
> channal attached to the image map - so I can't really do this.

Extract the alpha channel to another file and use it as an image_pattern? Or
did I miss the boat here?

Post a reply to this message

I second JRG's option. I ran recently into a similar problem and using
image_pattern was the way to go. An added benefit was the possibility of
using JPEG instead of extremely large TGA or PNG.

G.

--

**********************
http://www.oyonale.com
**********************
- Graphic experiments
- POV-Ray and Poser computer images
- Posters


news: 3be536c2@news.povray.org...
>
> "JRG" <jrg### [at] hotmailcom> wrote in message
> news:3be53443@news.povray.org...
> > Instead of using a color_map to define transparent and non-transparent
> areas
> > use a texture_map.
>
> I'm using an image map with the transparent areas defined by the alpha
> channal attached to the image map - so I can't really do this.
>
> Mick
>
>
>

Post a reply to this message

"Mick Hazelgrove" <mic### [at] mhazelgrovefsnetcouk> wrote in message
news:3be536c2@news.povray.org...
>
> "JRG" <jrg### [at] hotmailcom> wrote in message
> news:3be53443@news.povray.org...
> > Instead of using a color_map to define transparent and non-transparent
> areas
> > use a texture_map.
>
> I'm using an image map with the transparent areas defined by the alpha
> channal attached to the image map - so I can't really do this.
>
> Mick

JRG and Tony have it right. Finish maps would be useful here but the only two
ways I've discovered to vary the finish across a surface with bitmaps are using
either a material_map or 3.5's image_pattern. Image_pattern is the friendlier of
the two, from both usability and system memory consumption, standpoints.

Just declare your pigment{} (and possibly normal{}) using your image_map and
then declare two textures that use these with different finish statements.
Finally create a grayscale image from your original image_map and use the map
part of the image_pattern statement to control the blend between the two
textures.

For perspective, a material_map would employ basically the same technique only
you would have to pre-declare up to 255 textures differing only in finish
(yech!).

I can't say at the moment whether the alpha will work better in the
image_pattern or is best left in the original image_map, since I haven't tried
that yet.

Good Luck!

Batronyx ^"^

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I think I see what you mean, I'll have to play - trouble is I'm short of
time at the moment - oh well.

Mick

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Hi Gilles

I've just read up image_pattern(three times) and I reckon I understand what
I've got to do now. Just have to find time to play!

Mick

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Hi Mick,

look to a recent thread of Alan Holding named "Uh oh.." in p.b.i.
Gilles made code suggestions regarding image_pattern for faking
specularmaps.

Norbert




"Mick Hazelgrove" <mic### [at] mhazelgrovefsnetcouk> schrieb im Newsbeitrag
news:3be58311@news.povray.org...
> Hi Gilles
>
> I've just read up image_pattern(three times) and I reckon I understand
what
> I've got to do now. Just have to find time to play!
>
> Mick
>
>

Post a reply to this message