Altocumulus clouds

Alto cumulus clouds are mid-level layers or patches of cloudlets in the shape of rounede clumps, or rolls.They are usually white or  grey and they side away from sun.These clouds very ocassionally cause rain.
Alto cumulus cloud tool that i had developed can simulate two types
1)Undulatus
2)Floccus


 UNDULATUS

Reference Image of alto cumulus-Undulatus cloud

Undulatus are the cloudlets that are arranged in nearly parallel lines.


     Though clouds exhibit a lot of variations they follow a pattern .so  in the above shown image cloudlets are distributed in a parallel fashion .
    In order to achieve this effect, instead of direct working on volumes i created  patterns in the VOPCOP .
   Then Data from VOPCOP is sent to VOPSOP (and i should really thank Ari Danesh for suggesting me an idea to import data from VOPCOP  into VOPSOP).
   In VOPSOP i generate pscale attribute where metaballs are  being copied to , based on the data from VOPCOP.

VOPCOP PATTERN IMPLEMENTATION

Pattern for Undulatus cloud Procedurally
Generated in VOPCOP

1 )      The Global variables Pixel Horizontal Position and Pixel Vertical Position are converted to vector as all the noise position deal with vectors.
2)       Then they are plugged into the position of the curl Noise through a tranform Matrix .From there they are plugged into Ramp VOP.
3)       A Fit range VOP is added to controll the width of the stripes.
4)     Again the global variables PHP and PVP are plugged into the position of the trubulent noise.the output from the fit range node  will drive the amplitude of the turbulent noise.
5) Curl Noise is used to bring the curvy and bit irregular parallel pattern.

Screen capture of Undulatus cloud done using VOPCOP and Metal Balls

FLOCCUS

Reference Image of alto cumulus-Floccus cloud

Cloudlets with cumulus kind of tufts with raged bases.

VOPCOP PATTERN IMPLEMENTATION

Pattern for Floccus cloud Procedurally
Generated in VOPCOP

1)  As done in in the last case the PHP and PVP are converted to vector from float and plugged into the position of a curl noise .Again the converted vector is plugged into Vein VOP which will drive the  amplitude of the curl noise.

2)Since the Floccus exhibits a kind of cellular pattern i used a Rounded hexes VOP with which i can imitate the pattern.the o/p from the curl noise is converted back to float and the first two components are plugged into S offset and T offset parameters of the Rounded Hexes VOP.

3)A complement of the Rounded Hexes is taken and plugged into the main turbulent noise operator.

Screen capture of Floccus cloud done using VOPCOP and Metal Balls