Table of Contents
The Frame_Step=n (+STPn) option introduces breaks in the order of rendered steps. It splits the order of rendered frames into a 'virtual' and a 'real' order.
'Virtual' order is the same as the traditional (used in POV-Ray™ 3.5) order described with Initial_Frame, Final_Frame, Initial_Clock, Final_Clock, Subset_Start_Frame, Subset_End_Frame. This order is what the scripts reads from initial_frame, clock_delta and other animation related build-in tokens in SDL.
'Real' order is a subset of 'virtual' order. It is every n-th frame where n is the value of Frame_Step. Selected frames are reordered (with ascending or descending order) according to the sign of Frame_Step option.
Frame_Step is supposed to use parallel rendering over one source with one location shared between instances of renderer.
Example 2.1. Influence of Frame_Step on generated files
The following command line:
megapov +Iscene.pov Initial_Frame=1 Final_Frame=5 +FN
causes the creation of files in such order:
scene1.png scene2.png scene3.png scene4.png scene5.png
while when using Frame_Step:
megapov +Iscene.pov Initial_Frame=1 Final_Frame=5 +FN Frame_Step=-2
causes a subset of it in the following order:
scene5.png scene3.png scene1.png
Frame_Step different than 1 works fine for those animations where variables are not passed between frames when using external files and where the next frame does not use values derived from a previous (in the meaning of virtual order) frame by other ways.
Apart from reading HDR images as image maps (see Section 2.6.6, “HDR (High Dynamic Range) image type”) MegaPOV also supports this file format for image output. Further information on this file format can be found in Section 2.6.6, “HDR (High Dynamic Range) image type” as well.
The file format identification character is H. Writing this file format is activated by the command line option
or the ini option