Chapter 2. MegaPOV References

Table of Contents

2.1. Options
2.1.1. Frame_Step
2.1.2. HDR (High Dynamic Range) image output
2.2. Expressions
2.2.1. Language directives
2.2.2. Built-in tokens
2.2.3. Functions
2.2.4. Internal functions
2.2.5. Polynomial solver in parser
2.2.6. Splines
2.2.7. Transforms
2.3. Camera
2.3.1. user_defined camera type
2.4. Objects
2.4.1. Common features
2.4.2. Text
2.4.3. Cloth simulation
2.4.4. Isosurface
2.4.5. Light Sources
2.5. Effects
2.5.1. Glow
2.5.2. Motion blur
2.5.3. Fur
2.6. Textures and patterns
2.6.1. Angle of incidence
2.6.2. Listed pattern
2.6.3. Projection pattern
2.6.4. Displace warp for patterns
2.6.5. Noise pigment
2.6.6. HDR (High Dynamic Range) image type
2.6.7. Bicubic interpolation for images
2.6.8. New camera_view pigment
2.7. Global Settings
2.7.1. Film exposure simulation
2.7.2. Custom tone mapping function
2.7.3. Radiosity
2.7.4. Mechanics simulation patch
2.7.5. Post processing

2.1. Options

2.1.1. Frame_Step

Włodzimierz ABX Skiba

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:


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:



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.

2.1.2. HDR (High Dynamic Range) image output

Christoph Hormann

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