How to maintain image ratio?
 

Hi everyone,

anyone know how to maintain a texture's (2d file image) ratio?

1. With a poly plane,
Texture>Planar Mapping>Keep Image Ratio - just doesn’t do it. It keeps assuming the aspect ratio of my poly plane (and filling up the entire plane).

2. With a Nurbs plane,
How do you fit the texture map onto the plane with correct Length-width ratio? (My map is very big). I tried mapping the Coverage attribute of the 2dTexturePlacement node to the file image. I can then see the proportion (ratio) and size of the map but how do you scale it down? The image is so big I can’t even grab the ends to scale! I just need it to fit on the plane with the correct ratio). Is the only way to do it to reduce the size of the texture? - in which case you lose resolution...

any help appreciated!

thanks
Lori

go to the attributes on your camera, and add a image plane, under the enviroments tab. Then open your image in there. This will keep your ratio the way it should be. Its not good practice to use a plane to put your ref pic on. One reason is the problem youve got now :)
Hoped that help..

why not just create a plane that has a matching aspect ratio? You've already figured out that Maya stretches or squishes the texture to fill the entire surface area.

As for the attribute editor; using a coverage of less than 1 in U or V will reduce the covered ared. More than 1 will essentially crop some of the texture that exceeds the surface area. However, it will be difficult to get the aspect ration exact in the AE.

The other fix, you also, already figured out, is to map it and apply the texture only to the areas the UVs cover, hence your loss of resolution. On resolution, as long as you're not doing the model for a game, or some other purpose that places limits on texture map size then you can use a larger map size. Just be aware that your file size will increase accordingly.

Good luck

i'm not using it to model though. So no go on the camera image plane idea. I'm actually texturing a plane which is part of a model.

ok so it seems like maya cannot map a large texture to a plane and keep it's UV ratio... nobody from any of the many other forums i've tried has been able to solve this.

that's a HUGE disadvantage! they should get it fixed!!! it's a real BIG problem!!

i know i can have work arounds and eventually get my plane scaled etc to the right size but i shouldn't have to do this for such a basic operation!!

anyhoo thanks guys for the sggestions!

cheers
L :)

With polygonal objects you should map the UVs so that a square checker texture doesn't show any kind of stretching or distortion. After that what ever square texture you map on it should be alright. Why square? Well, it comes from the 0,0 - 1,1 UV area being square in nature. That said you should make your textures square too.

So if you have a texture file which is 256 x 512, it is better to increase the image canvas size to 512 x 512 than to try and correct the stretching some other way. That said it is also a good idea to try and layout the UVs so that there is minimum amount of empty space in the 0,0 - 1,1 area.

I remember reading somewhere that square file textures are even faster than non-square ones because Maya will handle all textures as squares anyway...

Nurbs have built-in UVs which you can't modify. Sometimes turning on the "Fix Texture Wrap" attribute in the shape node helps. Rebuilding the nurbs surfaces to as uniform as possible also helps...

Lori

Post a screen grab

_J

hi guys

figured out that if you just note the image proportions of the file texture and it's too big to scale down (manually - by grabbing the interactive placement gizmo), just type in a lower value keeping the same ratio - till you get it about right. then you can strat to manipulate it manually. that should do it!

(no screen grab at the mo jango - haven't got my maya here. but it's ok got it working now. thanks)

cheers
guys
Lori