9.5.2

820 • CHAPTER 18
MATERIAL EDITOR • 821
Circle
Circle sampling uses a circle of texture pixels (the ones surrounding the intermediate value). Textures
that are enlarged at render time tend to look more natural with this type than with the None type.
However, as the examples demonstrate, straight lines are problematic and tend to look frayed. In
addition, the texture is very jagged near the horizon. Circle sampling is, however, a good choice for
very small textures (e.g. 3 x 3 pixels), because it helps the pixels to blend softly.
Square
Square uses a square of texture pixels (the ones surrounding the intermediate value). This leads to a
softer transition between texture pixels than with None. The picture quality is good.
Alias 1, Alias 2, Alias 3
Alias 1, Alias 2 and Alias 3 blend the texture more strongly than Circle and Square. Alias 3 blends the
most, Alias 1 the least. In the example above, the texture is difcult to recognize with Alias 3 because it
is so small (16 x 16). Alias 3 can give smoother results than Alias 1, but it also takes longer to calculate.
However, even Alias 3 cannot prevent jaggies near the horizon!
MIP, SAT
Enable MIP Falloff to enhance the MIP/SAT mapping effect for bump maps.
This will reduce the strength of the bump map with increasing distance from
the camera.
MIP stands for ‘multum in parvo’, which is Latin for ‘many things in a small place’. When many texture
pixels effectively lie within a single screen pixel, an approximation is made based on the (known)
texture pixel values. This results in very smooth blending. MIP is the default sampling type.
SAT is short for ‘summed area tables’ and it does an even better approximation than MIP mapping.
As with MIP mapping, the approximation is based on the texture pixels that lie within a single screen
pixel. SAT is the highest-quality sampling type.
SAT mapping works with textures up to 4,000 x 4,000 pixels. CINEMA 4D
switches to MIP mapping automatically if you try to use SAT mapping with
textures over this limit.
MIP and SAT mapping are especially important for high-quality animation and for objects in stills that
extend towards the horizon, such as a sea. MIP mapping is the default sampling type. The following
two pictures demonstrate MIP/SAT mapping. Figure 1 was rendered with the antialiasing set to Always
with 2x2 oversampling. The tiled texture used Circle sampling. Although the quality is generally good,
the quality rapidly deteriorates towards the horizon. This unwanted effect is the result of perspective
distortion. Each screen pixel representing the oor near the horizon contains perhaps hundreds or
even thousands of texture pixels.