## FRACTALS |

FRACTAL ON VOLUME

FRACTAL ON FACET

A recursive subdivision algorithm associated with a process stochatique can generate a pleated surface from a grid mesh quadrilaterals.

Practically, the algorithm is that of Loren Carpenter

(modèle de terrain)

The random values are selected from a random table precomputed (whose dimension, in the initialized envb.h file, can be dynamically changed by the command dim alea). The animation random values are preserved from one image to the next.

`frac vol n=t,e,c;`

bit 0: along the vertex normal

bit 1: along the x axis

bit 3: along the y axis

bit 3: along the z axis

1) yes frac required to activate the fractals.

2) Le coefficient c represents la fraction (random displacement) / (facet size)

`frac vol 1=1,3,.5;`

defines fractalisation along the normal, order
3 with random .5
`frac vol 1=4,3,-.5;`

defines fractalisation along y axis, order 3 and random-.5 (inwardly of the volum).
`frac vol 1=3,3,.2;`

defines a fractalisation in a direction normal to the average between the facet and the axis of x.
`frac fac(f)vol(id)=t,e,c;`

defines a fractalisation on facet A geometric discontinuity appear at the junction of two fractalized facets with different coefficients.

(help frac)