Open GL ES Texture image quality

Question

Hello,

I have been having a bit of trouble with this issue with a while and have decided to ask for help!

I have a textured 1024 x 1024 area in my iphone application. I am texturing it using an image that i converted to .pvr4 format using Apples texturetool.

Now the user has the option of zooming in on this textured object....

The issue is that the quality of the image is not good enough when it is at the highest zoom level.

How can i improve this?

Should i be looking at mip mapping?

Any pointers in the right direction would be greatly appreciated.

Thanks

Tom

Answer 1

PVR4-compression is rather destructive. Simply choose another format if texture quality is crucial.

Answer 2

If you zoom in enough on any texture, you won't see much detail.

Here are your options:

• You can change the magnification filtering mode so that instead of being blocky (nearest filtering), it's blurry (linear filtering). (Or vice-versa.)
• Don't use PVR texture compression. This will make your texture more detailed. (But at the usual cost: larger size, slower rendering.)
• When zooming in, switch to a more detailed texture for that specific area.

The last option is the most work, but will likely give the best results. (But try the other two, they're easy.)

Also, mip-mapping likely won't help your situation. In general, enabling mip-mapping can make textured objects far away from the camera look better. It usually doesn't have any effect when the camera is close to a textured object.