PDA

View Full Version : How can I do this? (texture issue)


Flimbo72
07-16-2005, 01:19 AM
Hello everyone,

I am trying to figure out how to do this silly task... repeating a texture around a flat disk.

I tried with a cylindrical projection around the Y axis (my disk is aligned to X-Z axis), using automatic sizing. The resulting OpenGL preview was encouraging (though the texture appeared mirrored), but the rendering gave me a completely blank disk!
Ironically, it is sufficient to lift the external edge of the disk, adjust the texture size with automatic sizing and everything works perfectly.

But with a flat disk what shall I do?
Am I forced to draw the whole texture round by myself and then apply it through a planar projection???

Just curious.
I hope everything is clear. I have pictures, but I don't know how to post them here.

Giacomo

blaqDeaph
07-16-2005, 05:28 AM
I'm not quite following you here, if its a flat disk, why would you want to wrap an image around the disk?

Can you post some pictures? If you are using the WYSIWYG interface (look in the user settings page) look at the toolbar, you should see an icon that looks like the insert picture in MS office, then type in the URL (it has to be hosted off site, like www.imageshack.com), and voila!.

evenflcw
07-16-2005, 11:57 AM
There's a popular technique for this from way back. Basically you start by projecting your image onto a square plane. Then bend that plane into a disc. Back when LW had no UVs, you had to do the bending via a morph or somesuch in Layout because front projections don't stick in Modeler. Nowadays we have UVs, so you can do it all within Modeler...

So, just create a plane with n segments, planar UV map it, bend it into a disc using the bend tool, then merge some points as you see fit. Checkout the attached gif animation.

EDIT:
"Ironically, it is sufficient to lift the external edge of the disk, adjust the texture size with automatic sizing and everything works perfectly."
You could use this technique aswell. But to get the cylindrical projection to stick when you flatten it, you would have to do the flattening via a morph (as I explained they did way back when). In this case, an alternative to morphing could be to scale the disc on Y to make it appear flatter, but imho this is a less elegant solution.

Flimbo72
07-17-2005, 12:28 AM
Thanks! I hoped it was easier, but your suggestion works well.

Here are the pics I wanted to show you.

My settings:
http://www.solisearch.net/ims/pic.php?u=22342got5o&i=142168

The pertaining OpenGL preview (why is the texture mirrored?):
http://www.solisearch.net/ims/pic.php?u=22342got5o&i=142169

The rendering:
http://www.solisearch.net/ims/pic.php?u=22342got5o&i=142170

Lifting the external points and adjusting the texture size, I obtain what I wanted, though the disk is not flat anymore...
http://www.solisearch.net/ims/pic.php?u=22342got5o&i=142192

evenflcw
07-17-2005, 06:15 AM
Ah, that's what your trying to do. Just a repeating texture, not stretched in a circular fashion (although they are kinda simular). For this you could just use UVSpider. It will follow a loop of quads and create a neat UV map.

So. just select the polygons in order and run UV spider. With the default settings UVSpider will fit everything within the UV square. To get the texture to repeat across the disc you need only stretch the UVs beyond this square. Attached another animated gif.

EDIT:
Attached another image of the texture settings, just in case ;)

Flimbo72
07-17-2005, 08:54 AM
Wow! That's cool, but where is the UVSpider tool? I cannot find it.
Is it a new tool that comes with Lightwave 8? I have Lightwave 7.0

evenflcw
07-17-2005, 09:30 AM
It's not particularly new. I don't know about 7.0, but it should be in 7.5, which you are entitled to (free upgrade).

Also, you really don't need UVSpider to do this. It just automates what you could do manually. I suggest you read some UV mapping tutorials to understand how UVs and the basic UV tools work. Once you've done that, you should have no problems creating them without the use of UVSpider.

CGTalk Moderation
07-17-2005, 09:30 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.