Kurtz le pirat wrote > Where am I wrong?

The misunderstanding came from pirate's statement "the difference between  
the two images is only the ratio of the source image map". Together with  
Slime's posting about the images that shold be "width = 2*height" it has  
caused confusion.
If both of you would refer to the width/height ratio of the NINE in your  
image it's alright.
Chris B is perfectly right in all his postings. I attached a zip  
filecontaining two scenes that should clear that fact. The zip file also  
contains the images in full size.
The first is - as you all (except etrask) did it - a cylindrical  
projection an a sphere. And it shows that it doesn't matter at all what  
the dimensions of the image are. Image "Nine_Band_sm.gif" is a 2048 x 512  
pixel image, and "Nine_Band_shrunk_sm.gif" is just made out of the latter  
by rescaling. Both will give the Niner the same appearence. I didn't post  
the rendered image cause it looks almost the same as the one that I post  
with the ...

  ... second example: It's not always necessary to use cylindrical  
projection in this cases where a relatively small image - the number nine  
- shall be glued to a billiard ball (are they're called "ball" by the  
way?). You also can use PLANAR projection in this cases. And with the  
planar projection you can fit your niners very nicely by scaling x and y  
seperately. Which you can NOT in spherical projection, there you can only  
scale the height. The width of your 9 can only be influenced with your 2D  
graphic program where you influence the width of our nine compared to the  
width of the image !
And again: it does NOT matter what height the image has got.
Really the x/y ration of an image never has an influence on its behavior  
in an image_map regardless if it is projected planar, spherical or  
cylindrical.


In my second example two niners are rendered with a gradient y to make the  
yellow stripe and two pictures of a nine, that differ only in their  
x-y-ratio (named Nine_sm.gif and Nine_stretched_sm.gif).
The red rim is made only to be filtered out in the rendering, as the nine  
is in a circle not in a square. Nice feature in the image_maps!




I posted this mainly because that ratio thing puzzled me also for quite  
some time.


Yours,
Bu.

Post a reply to this message

Attachments:
Download 'billiard_9.zip' (43 KB) Download 'nine_band_sm.gif' (4 KB) Download 'nine_band_shrunk_sm.gif' (3 KB) Download 'nine_sm.gif' (3 KB) Download 'nine_stretched_sm.gif' (3 KB) Download 'billiard_9_planar.png' (40 KB)

Preview of image 'nine_band_sm.gif'

Preview of image 'nine_band_shrunk_sm.gif'

Preview of image 'nine_sm.gif'

Preview of image 'nine_stretched_sm.gif'

Preview of image 'billiard_9_planar.png'