 ```I've had some time to look around in the VBscript references and I have found
some more math functions that a very useful in 3D.```
```                               abs(x)
y^x
x mod y
int(x)```
```The first one is the power function, in combination with a sin or cos, can
produce varying result.```
```

As you can see this function is very useful to create random fcurves. The next
one is the Int( ) function, this one is very useful in modeling.

TASK: Try to model a DNA structure, with the knowledge of math101 and math102
you should have no problem. A DNA structure is made up of to helix, not to
be confuse with a spiral. To help you out this is the math function for a
helix:
x = r cos t
y = r sin t
z = ct

where r is the radius of the helix and c is a constant
giving the vertical separation of the helix's loops. t is
the tangent

You should get something that looks like this image, actually this
is a triple helix model that I did for my project: "Code Name: THX"
The DNA structure is a double helix and in my next tutorial I will
explain how to do the middle part of the structure ``` ```

dim i
dim x
dim y
dim z
dim num_cv
dim increment

i=0
x=0
y=0
z=0
num_cv=100
increment= 0.2

SICreateCurve "crvlist", 3, 0

do while i <= num_cv

i=i+1
x=increment+x
y=abs(sin(1.5^x)*5)
SIAddPointOnCurveAtEnd "crvlist", x, y, z, False

loop

dim i
dim x
dim y
dim z
dim num_cv
dim increment

i=0
x=0
y=0
z=0
num_cv=100
increment= 0.1

SICreateCurve "crvlist", 3, 0

do while i <= num_cv

i=i+1
x=increment+x
y=int(x mod 2)
SIAddPointOnCurveAtEnd "crvlist", x, y, z, False

loop

```
```

```  This tutorial courtesy of Eric Poirer and XSIStation