Game Development Reference
In-Depth Information
with them. However, behind the curtain, Unity is quietly converting the
non-power-of-two textures into power of two versions. In Unity 2.x and
earlier, Unity had to be told to do this, but now Unity assumes you mean
to and chugs away on import bending the files into the size that they will
work fastest with.
However, resampling an image that is just off of power of two (say 520×520)
down to 512×512 can lead to muddy images. It can be tough for software to
know exactly which pixels to leave out as they resize down, or which pixels to
double when resizing up.
Ultimately, creating textures as power-of-two texture will yield time-saving
results on import and create crisper images that MIP Map (more on this later)
better and play quicker on all video cards.
Seamless Textures
Some of the UV Mapping we have completed works on the idea that
each pixel of the texture is shown once, and only once on the surface it is
applied to. This can yield really intricate textures, but is sometimes hard to
maintain good resolution without monstrously large files (and thus lower
frame rates). For other maps (like the floor, for example) we built a UV
map with the assumption that we were going to repeat, or tile a texture.
This means that instead of seeing one 1024×1024 texture spread across
our entire dock (which would mean a very few muddy pixels being visible
when we look down at our feet), we could repeat that texture many times
so that we could (in theory) see the entire 1024×1024 texture right at
our feet. This allows for a texture that holds up much better upon close
inspection.
However, when a texture is going to be repeated like this it becomes critical
that there are no seams as the texture tiles. If the top of the texture doesn't
line up perfectly with the bottom, the tiling will be seen and the illusion of an
unbroken surface will be destroyed.
Maya and Unity
Luckily, the Unity paradigm for describing Textures/Materials/Shaders is
virtually the same as Maya's. It is part of why Maya and Unity make such a
good pairing. If you understand the creation of materials in Maya, moving into
Material and Shader creation in Unity will be much smoother.
However, having said this, some data is lost in the .fbx conversion process
when moving assets from Maya to Unity. Unity deals with .fbx files. What it
does with most any model that it imports is convert that model from Blender
or Maya or C4D or whatever into an .fbx file. Unfortunately, complex shader
networks created in Maya do not transfer as is into Unity. There almost
always is some rebuilding when the assets move from Maya (or whatever 3D
application you're using) into Unity.
