Description Data structure for a Diffuse Polynomial scatter model. The diffuse polynomial scatter model has the following mathematical form:
The value of imax is the following:
In all cases, imax is always non-negative and the summation i = 0 to imax always has at least one value (i=0) where the summation occurs.
The parameters U, V, W and T have the following meaning, where (a0,b0) is the specular direction and (a,b) is the scatter direction. U = a2 + b2 V = aa0 + bb0 W = a02 + b02 T = (a-a0)2 + (b-b0)2 = U - 2V + W
Definition Type T_DIFFUSEPOLYNOMIAL Name As String Description As String ApplyRefl As Boolean ApplyTrans As Boolean HaltIncident As Boolean n As Long m As Long L As Long lMode As Long lp As Long D As String End Type
Members Name Name of the model.
Description Description of the model.
ApplyRefl Determines if the scatter model is applied on reflection.
ApplyTrans Determines if the scatter model is applied on transmission.
HaltIncident Determines if the scatter model halts the incident ray.
n Upper summation index (see equation above).
m Upper summation index (see relation to imax in the equation above).
L Upper summation index (see l in the equation above).
lMode This value toggles the interpretation mode of the summation index limits for the polynomial. For historical reasons, there are three summation modes (values 0-2). Options are the following:
lp Lower summation index (see l' in the equation above).
D Constant (see equation above).
Used as Parameter in
Examples
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