Table of Contents
Texture patterns and look up table
Pattern: Waves
Definition: t = (1+sin(freq*xt))/2.0
attribute = a0+t*(a1-a0)
Call: hfA_Wave(xt,a0,a1,freq);
Parameters:
xt - point coordinate
a0,a1 - Interval in between the returned value belongs
freq - Frequency
Output : A value between [a0,a1]
Test file: hfA_Wave.hf
Pattern: CheckerBoard
Call: hfA_CheckerBoard(x,bricks,space,s, c_bricks,c_space);
Parameters:
x - point coordinates array
bricks - Size of the bricks. (3D : width,lenght,wide)
space - Size of the spaces between the bricks. (3D : width,lenght,wide)
s - Output Array
c_bricks - array of attributes corresponding to the bricks
c_space - array of attributes corresponding to the spaces
Output : attributes in the s array
Test file: hfA_CheckerBoard.hf
Pattern: Crackles
Definition : A “noisy” value p is calculated. According to the map array, attributes are applied.
Call: hfA_Crackles(x,s,freq, attributes,maps);
Parameters:
x - point coordinates array
s - Output Array. Size k
freq - frequency of the pattern
attributes - set of array of attributes. Size k(n-1)
maps - array of n+2 values :[0,a1,…an,1]
Output : attributes in the s array
Test file: hfA_Crackles.hf
Pattern: Concentric Circles (centered around the origin)
Definition : Periodic circular areas are calculated, and attributes are set according to the map array.
Call: hfA_Circles(x,s , attributes,maps);
Parameters:
x - point coordinates array
s - Output Array. Size k
attributes - set of array of attributes. Size k(n-1)
maps - array of n+2 values :[0,a1,…an,1]
Output : attributes in the s array
Test file: hfA_Circles.hf
Look up table
Definition : Given a set of intervals (array of n values in [0,1]), and given a set of colors (array of 3*(n-1) values), each set corresponding to an interval, and given a value t in [0,1]. Depending on the interval t belongs to, a set of attributes is set.
Call: hfA_LookUpTable(t,s,c,map)
Parameters:
t - Real value
s - Output array (attributes)
c - Input array (attributes)
map - Input array (interval)
Output : attributes in the s array
Test file: hfA_LookUpTable.hf
Smooth Look up table
Definition : Given a set of intervals (array of n values in [0,1]), and given a set of colors (array of 3*(n-1) values in the case of rgb attributes), each set corresponding to an interval, and given a value t in [0,1]. Depending on the interval t belongs to, a set of attributes is set. A linear interpolation is performed between the set of attributes corresponding to the lower and upper boundary of the interval where t belongs to.
Call: hfA_SmoothLookUpTable(t,s,c,map)
Parameters:
t - Real value
s - Output array (attributes)
c - Input array (attributes)
map - Input array (interval)
Output : attributes in the s array
Test file: hfA_SmoothLookUpTable.hf