Hello Bernie,

on Samstag, 15. September 2007, 13:33:32, you wrote:

> I typically name my textures like this:

> B_texture.jpg - Bump
> D_texture.jpg - Diffuse (colour)
> A_texture.jpg - Alpha (scope or fade)

> So in the material now - you simply copy and paste the path (whatever 
> the texture was that you just browsed the path to and is now selected in
> the colour field) into the scope path dialog, then just change the D_ to
> A_ and thats it ! (This is my methodology and I find it completely 
> painless)

Yes, good technique. Something similar I’ve also used. But I would
never use JPG files as textures. Simply because JPG adds noise to the
image. Normally not visible not visible by simple looking at the image
on the screen, but when heavy calculation are done on the image are
done in VSL, the noise could be emphasised, and therefore visible in
the final rendering.

> You can even copy and paste the path directly from Dir Opus as well.

Ah, a DirOpus user like myself. Nothing beats DirOpus, it’s a must
have!   :-)

>> BTW: I would never ever use Gif files in combination with RS3D! 
> ? I use them all the time to good effect.

> Have a look here:

> http://www.vrgrafix.com.au/Gallery.html?&tx_gooffotoboek_pi1[srcdir]=48-Kambah

> Note the word "signage" ? Thats simply a GIF file with transparency.

Mhh, I don’t know, but I see lots of noise. For example in this image:

http://www.vrgrafix.com.au/fileadmin/user_upload/Gallery/48-Kambah/VR_10-09-2007_View3.jpg

It doesn’t look like JPG artifacts. Haven’t you used AntiAliasing?

>> doesn't provide a true alpha channel. They only provide a 1 Bit mask.
> correct. But in an on/ off affair such as this example, as long as the
> image has a high enough resolution this is not an issue.

The problem is that the transparency information of a GIF file isn’t
an apha channel! That’s why it is called Fade inside RS3D. The fade
channel of a GIF file defines where the transparency is, but a alpha
channel like the alpha channel of a PNG file defines where the colours
are. So, to map the fade channel of a GIF image to the scope channel
inside RS3D I have to add an Operation object with 1-p1 to convert the
fade channel to an alpha channel. Theoretically this would raise the
rendering time. Ok, practically not really measurable I think.   :-)

> Also GIF images are great for large rez images (3-5k) such as B+W site

Ok, here begins now the hard part. For the last days, I’ve sit down
and thought “What’s the best image size and colour depth when used as
a texture?” I haven’t found a text which describes this. I’ve only
found some rule of thumb like “Use image resolution twice as big as
your final rendering resolution”. But no description why I should use
this rule of thumb! So, I sit down and worked it out. I digged deeply
in the field of signal processing and such alike. It’s not final
yet, but in the next days I will post another message which will
explain my work. Please wait for it.

> overlays etc. (Small file sizes = faster render times)

I don’t think that the size of the texture file on disk has anything
to do with rendering time. Simply because RS3D has to decode the file
to access the information inside. And the decoded format is every time
the same.
-- 
Best wishes,
 Marc Michael

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