textures with lines and angled prim faces

Can anybody point me in the direction of any good beginner to advanced texture creation tutorials available offline, that specifically covers how to for SL. I’ve looked round on the resident sites but can find anything that solves a problem ive encountered.



I’ve found Julian Fates How To: Texture Zones, tutorial excellent though it is it doesn’t solve my problem.



Or if anybody can explain how to solve this problem...



Please see the attached image.



As you can see from the image ive got a prim with slanting faces and any texture with straight lines distorts where the prim is angled greater or less than 90 degrees. What is the best way to solve this problem?



Just a side thought is it possible to export the (UV) meshes of SL objects, that might go a long way to solving my problems?

Hi Shakaar, under the texture tab in the Edit menu, there's an option to set the texture mapping from "Default" to "Planar" - this and some tweaking of the X/Y repeats should fix the problem.

As for the UV maps of the various primitives, I'd recommend a visit to Robin Sojourner's excellent texture tutorial in-world - it's in her picks - which explains that (and other topics).

What you're seeing is absolutely normal for polygonal modeling with standard, non-planar UV mapping. It has to do with the fact that every shape in 3D computer graphics is made out of triangles. A rectangle is not really a rectangle, but two right triangles, arranged hypotenuse to hypotenuse.

When you shorten one end of a rectangle, you distort the two triangles in different ways. One has just one point move, while the other has two points move. This results in half your texture just bending a bit while the other half gets both bent and squished.

In SL, to fix this problem, it used to be that we had to employ relatively complex methods of negatively pre-distorting textures in Photoshop to offset the positive distortion caused by the bent and squished triangles. The method worked pretty well if you knew what you were doing, but it required a unique adjustment for each possible degree of top-sizing on the prim. Needless to say, it was pretty time consuming if you wanted to do anything close to the full range.

Nowadays though, doing all that work by hand is completely unnecessary. LL gave us planar mapping a while back, and it solves the problem completely. Simply change the mapping type for the object (on the texture tab on the editor) from standard to planar, and the texture will straighten out.

Be aware that planar mapped textures get measured in absolute, not relative units, so you may need to adjust your repeats and offsets. Everything for planar maps in SL is measured in repeats per meter, not repeats per face.

For more on planar mapping, see this thread.

And as Jackal said, check out Robin's inworld tutorials. They're very good.

[left]many thanks Jackal and Chosen. looks like ill be heading back to Robins place again... this time i might actually learn something
[/left]
Chosen: The points you made about pre-distoring textures had me sweating a bit, thought i was going to have to do something bad like that when i posted, phew

thanks again
now if only LL answered questions as quick as you guys

Thanks for the kind words about my tutorials, everyone.

At the moment, I'm in the process of updating them to explain Planar mapping, especially. Planar mapping on flexiprims (which is amusing as all get out to watch, especially on the Prism, but probably not terribly useful. Try it and move the prim around for a laugh, though! Be sure to set the flex to something that will wobble like jello. It's even more amusing that way.)

Suffice it to say that although Planar mapping is going to work perfectly on prims that aren't flexi, on flexiprims you'll still want to pre-distort the image.

Let me know if the prims you need are flexi, and I'll give you more info.

Hope this helps!