The <#526#>cblob<#526#> primitive was provided by George McGregor
<#527#>;SPMlt;mcgregor@ncifcrf.gov;SPMgt;<#527#>
The <#536#>flame<#536#> primitive was provided by Reto Mani <#537#>;SPMlt;mani@iam.unibe.ch;SPMgt;<#537#>
The <#542#>seed<#542#> value is the seed for the random number function. The seed value specifies the shape of the surface -- changing the seed value will randomly change the surface shape.
The <#543#>subdiv<#543#> value is the number of subdivisions for the surface
--
The number of points in the surface follows the following formulas,
where <#545#>Size<#545#> is the total points per side of the object:
The four corner points will always have an altitude of zero, the
maximum altitude should never be never be more 1.0 and the min should never be
less than -1.0.
The <#546#>fracland<#546#> primitive was provided by Larry Coffin
The curve that is rotated is of the form
The <#570#>rotspline<#570#> primitive was provided by Gerald Iles
Hopefilly the following examples make this clearer:
There are a few known bugs:
Other problems:
Using third order equations to define the center path or the radius
requires solving a tenth order equation when checking for intersection. All
roots over the interval (0, 1) must be found, not just the smallest. The root
finder used was one that I wrote that uses a combination of Newton-Rasphson and
bisection. It ends up being fairly slow and probably could use some speeding
up. A few possibilities would be using Sturm sequences to find the number
of roots over an interval (I tried this but my algorithm did not find all the
roots and thus produced gaps in the surface. I plan on trying to fix it if I
can) and to reduce the polynomial by dividing through by known roots before
solving for remaining roots.
Any comments, bug reports, or suggestions for changes or improvements
will be greatly appreciated.
This addition provided by Larry Coffin
<#547#>;SPMlt;lcoffin@clciris.chem.umr.edu;SPMgt;<#547#>
Creates a solid of revolution. This primitive can be defined in two ways.
<#571#>;SPMlt;ilesg@p4.cs.man.ac.uk;SPMgt;<#571#>
This primitive is defined as a sphere of varying radius swept, or
extruded along a path in space. The path is defined in one of several ways.
The path can either be defined as four points which define a bezier path, where
the path passes through the first and last endpoints with the second and third
points defining the slope or tangent line for the curve at the first and last
points.
A second way to define the curve is to specify the coeffecients for
the parametric equations that define the curve. This is specified as
``<#583#>coeffs<#583#> fx fy fz'' where each fn is a third order equation,
c0 c1 c2 c3, where
A third way is to use any combination of parametric bezier curves
or function coeffs. These are specified as <#589#>nbezier<#589#> or <#590#>ncoeffs<#590#>
where n is x, y, or z. These are followed by four numbers that are
interpreted as the coeffecients for the parametric variable x, y, or z
in the case of <#591#>ncoeffs<#591#> or as the bezier curve where the first number is
the starting value, the last value is the ending value, and the second and
third values define the ``speed'' at which the curve leaves the endpoints.
<#597#>bezier -10 0 0 -10 0 0 10 0 0 10 0 0<#597#>
and <#598#>bezier -10 0 0 10 0 10 -10 0 10 10 0 0<#598#>.
<#600#>lcoffin@clciris.chem.umr.edu<#600#>