Newbie: Some UV Mapping Questions

1.) Is it possible to UV map an alpha transparency? Like suppose I made a cutout image in Photoshop with a transparent background, and then I UV mapped it to just a plane in Blender. I want just the cutout to show up, not the rest of the plane, so how do you set Blender UV maps to keep the transparency?

2.) Whenever I do UV mapping, the UV maps always seem to be turning out jaggy, even if the surface is just a plane. On the contrary, I’d actually like to render images that could be of print quality, so I need something highly refined even at around 300 dpi. The thing I dont understand is what “Blender Units” are - they dont seem like pixels per inch, or anything I’ve seen before. Anyway, when you are UV mapping an image - how do you:

2.a.) In Blender, identify the number of pixels in your face? This would allow me to at least predict the layout image quality in Photoshop beforehand, but he numeric transform doesnt seem helpful, unless I’m missing something.

2.b.) In Photoshop, create the best resolutions possible for UV mapping?


Mr Head
Simply use MapInput UV.

You can’t directly.
-> How large is the face viewed from your camera?
-> How many pixels has the render result?
A face with one Blender Unit may cover 1/100 of your aperture or be 100 times larger.

A rule of thumb would be to make the texture two times larger in X and Y direction than it is visible later in the picture.

You might try and turn off MipMapping and use CatRom or Gauss Filter.

Very cool on the first tut. :slight_smile:

Your questions are helpful, as they lend direction, but I’m not sure how I could apply them to your rule of thumb yet.

Thanks again,

Mr Head

Lets say the face is visible on a quarter of your rendered image. The image shall have the dimensions

So your texture needs something around 2 160 000 Pixels.