Note: Before editing any files or textures, always make a backup copy of them first!
Sometimes when looking at your aircraft in external views, or looking at AI aircraft, the textures will appear blurred. This is often caused by the skin for that aircraft model having 'mip maps' saved into the file. This tutorial will briefly explain what mip maps are, and how to remove them from an aircraft skin.
First, what is a mip map and why do they blur? A mip map is a set of lower resolution versions of a texture, all saved together inside a single file. Each smaller version is 1/4 the size of the previous. In computer simulations, as a 3D object moves farther from our point of view, the level of detail visible in it's textures decreases.
Below is a sample image showing a texture which has mip maps.
With a texture without mip maps, the computer has to process the texture file as it is rendered smaller on the screen, and sometimes there will be artifacts from this processing. Also, there is some wasted processing power in having high resolution textures shown on objects which are only rendered as a few pixels on screen. Using mip maps allows the simulation to 'down shift' to a smaller texture version as an object is rendered farther away, and since the rendered texture is lower resolution, there are less texture pixels being rendered on those distant objects.
A side effect of mip map textures is that sometimes they are not rendered at full resolution when they are near our point of view in the simulator. This is when we see a blurry texture, as the simulator has chosen a lower resolution version from the saved mip maps, and we plainly see the low resolution texture.
Removing the mip maps from a skin is usually as simple as a few mouse clicks using a program called DTXbmp, which is avaliable from MW Graphics
. Check the program list link for "DTXbmp".
Open up a texture in DTXbmp and you'll see a few tool bars. The option for removing mip maps is very easy to spot, shown below.
Just empty the check box, and save the file in the appropriate format. That's it! Here's the results, no more blurry textures.
It's worth noting that in some cases mip maps can be useful for improving performance, such as on AI aircrafts. These aircraft are often far away and rendering full resolution textures on them might hurt performance on some systems.