Update

aliasing.md

@@ -52,7 +52,7 @@ Of course this doesn't only happen with perfect sine waves. [Fourier transform](
 
 Aliasing is also a common problem in [computer graphics](computer_graphics.md). For example when rendering textured 3D models, aliasing can appear in the texture if that texture is rendered at a smaller size than its resolution (when the texture is enlarged by rendering, aliasing can't appear because enlargement decreases the frequency of the sampled signal and the sampling theorem won't allow it to happen). (Actually if we don't address aliasing somehow, having lower resolution textures can unironically have beneficial effects on the quality of graphics.) This happens because texture samples are normally taken at single points that are computed by the texturing algorithm. Imagine that the texture consists of high-frequency details such as small checkerboard patterns of black and white pixels; it may happen that when the texture is rendered at lower resolution, the texturing algorithm chooses to render only the black pixels. Then when the model moves a little bit it may happen the algorithm will only choose the white pixels to render. This will result in the model blinking and alternating between being completely black and completely white (while it should rather be rendered as gray).
 
-The same thing may happen in [ray tracing](ray_tracing.md) if we shoot a single sampling ray for each screen pixel. Note that [interpolation/filtering](interpolation.md) of textures won't fix texture aliasing. What can be used to reduce texture aliasing are e.g. by [mipmaps](mip.md) which store the texture along with its lower resolution versions -- during rendering a lower resolution of the texture is chosen if the texture is rendered as a smaller size, so that the sampling theorem is satisfied. However this is still not a silver bullet because the texture may e.g. be shrink in one direction but enlarged in other dimension (this is addressed by [anisotropic filtering](anisotropic_filtering.md)). However even if we sufficiently suppress aliasing in textures, aliasing can still appear in geometry. This can be reduced by [multisampling](multisampling.md), e.g. sending multiple rays for each pixel and then averaging their results -- by this we **increase our sampling frequency** and lower the probability of aliasing.
+The same thing may happen in [ray tracing](ray_tracing.md) if we shoot a single sampling ray for each screen pixel. Note that [interpolation/filtering](interpolation.md) of textures won't fix texture aliasing. What can be used to reduce texture aliasing are e.g. by [mipmaps](mipmap.md) which store the texture along with its lower resolution versions -- during rendering a lower resolution of the texture is chosen if the texture is rendered as a smaller size, so that the sampling theorem is satisfied. However this is still not a silver bullet because the texture may e.g. be shrink in one direction but enlarged in other dimension (this is addressed by [anisotropic filtering](anisotropic_filtering.md)). However even if we sufficiently suppress aliasing in textures, aliasing can still appear in geometry. This can be reduced by [multisampling](multisampling.md), e.g. sending multiple rays for each pixel and then averaging their results -- by this we **increase our sampling frequency** and lower the probability of aliasing.
 
 **Why doesn't aliasing happen in our eyes and ears?** Because our senses don't sample the world discretely, i.e. in single points -- our senses [integrate](integration.md). E.g. a rod or a cone in our eyes doesn't just see exactly one point in the world but rather an averaged light over a small area (which is ideally right next to another small area seen by another cell, so there is no information to "hide" in between them), and it also doesn't sample the world at specific moments like cameras do, its excitation by light falls off gradually which averages the light over time, preventing temporal aliasing (instead of aliasing we get [motion blur](motion_blur.md)).