3 replies to this topic

[noatom]

So I have a surface that is 129 x 129 vertices.And that surface must be textured.
This is what's happening: I'm gonna use a 2000 x 2000 texture.

First time,I will just simply use it,I'll just sample from it.Here's the result:








Now,I'll do something else.I'm gonna tile the texture.So this is what I'll do: multiply every vertex's texture coord. with 5. This is the result:



NOTE: Ignore the water!! Also,the same exact texture is used in both cases.

The question is: Why the first time when I use nothing but the raw texture,everything looks so big(no minification),and the second time when I actually repeat the texture 5 times,minification appears?

[Seabolt]

Minification happens when multiple texels map to a single pixel. So when you are using a giant texture in a small space, you'll never see minification unless you zoom fairly far out, and a 2000x2000 texture is fairly large. But when you tile that texture, you're forcing more texels map to a smaller area, causing it to hit the min filter.

[noatom]

So If I make a 10.000 x 10.000 image in photoshop,and add those 2.000 x 2.000 images 5 times,to fill that 10.000 image,and put that image in my app,would I get the same results as I got in photo 2?

(actually tried that,app crashed:))

Edited by noatom, 15 August 2012 - 04:21 PM.

[Seabolt]

Basically think of it this way, if you have a surface area of 256x256 and a texture that is 512x512 would you have to stretch the texture to fit that area, or shrink it? If you have to shrink it, you'll hit the min filter, if you have to stretch it, you'll hit the mag filter.