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- non-componentwise color interpolation in combiners \\ |
- non-componentwise color interpolation in combiners \\ |
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READABILITY - screen gamma |
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\fi |
\fi |
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\subsection{Basis textures} |
\subsection{Basis textures} |
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We call the textures assigned to each OpenGL texture unit {\em basis textures}. |
The shapes of the final background texture are generated |
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entirely from a small set of {\em basis textures} which |
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are the textures actually |
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assigned to OpenGL texture units. Even though the basis |
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textures are RGB textures, they contain no color information: |
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they are simply treated as 3-vectors to be used in |
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various ways to create shapes, and color is added |
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by the register combiners. |
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In order to avoid shapes or features from the basis textures becoming |
In order to avoid shapes or features from the basis textures becoming |
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identifiable, the basis textures should be relatively uniform. |
identifiable, the basis textures should be relatively uniform. |
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We have obtained good results with a mix of |
We have obtained good results with a mix of |
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small textures with uniformly random texels, |
small textures with uniformly random texels, |
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larger textures with noise or turbulence\cite{perlin-noise-intro}, |
larger textures with noise or turbulence\cite{perlin-noise-intro}, |
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and simple geometric images (e.g. checkerboard, see Fig.~\ref{fig-basis}). |
and simple geometric images |
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(e.g. checkerboard, see Fig.~\ref{fig-basis}). |
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As for selection of basis textures for each paper, the principle of ``saving bits'' applies: |
As for selection of basis textures for each paper, |
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using hyperparameters for each paper to control the probabilities of |
the principle of ``saving recognitive power'' applies: |
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different basis textures so that a paper will have mostly basis textures |
we use hyperparameters for each background texture |
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of one or two types will give a specific feel to the paper. |
to control the probabilities of |
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selecting different basis textures so |
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that each paper will mostly have only basis textures |
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of one or two types. |
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% will give a specific feel to the paper. |
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% XXX: and how does that amount to maximising entropy? |
% XXX: and how does that amount to maximising entropy? |
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% - different types of shapes are not orthogonal to perception |
% - different types of shapes are not orthogonal to perception |
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