formZ SDK | 4.0 Call Back Reference
Description
formZ renderer callback functions. This section describes the functionality needed to
create a plugin Renderer.
In formZ, there are seven built-in rendering types: Wire Frame, Interactive Shaded, Quick Paint,
Surface Render, Hidden Line, Shaded Render and RenderZone. Additional rendering types may be
added by creating a renderer plugin and registering a callback function set, which provides
functions called by formZ to render the modeling scene on the screen. Each plugin renderer
will automatically be added to the Display menu, below the standard formZ renderers. In
general, a plugin renderer will fall into one of three categories: vector line or polygonal
drawing, such as Wire Frame, Hidden Line or Quick Paint, interactive rendering such as
Interactive Shaded or static pixel based rendering, such as Shaded Render or RenderZone.
Depending on the category, different screen drawing methods need to be used. Vector and
polygonal renderers may draw directly to the screen. Interactive renderers usually employ some
kind of hardware assisted display. Static pixel based renderers must use the formZ supplied
image buffer to store and display the image. A renderer should represent the modeling scene in
a faithful manner. That is, the projections of the objects on the screen should match those of
the other rendering types. formZ offers utility functions, which facilitate the transformation
of a 3d point through the display pipeline to the screen space. If a renderer provides a shaded
display of the scene, surface colors and lighting should be taken into account. While it is not
possible to execute the RenderZone shaders of a surface style in a plugin, the renderer is free
to create its own artistic or realistic shading of surfaces based on the color of a surface
style or based on its own surface style attribute. Lighting effects can be incorporated in a
renderer anywhere from simple to accurate illumination. All parameters of the lights in a scene
can be retrieved by a renderer through formZ API functions. It is up to the renderer whether or not to use
this information to create the illumination of the shaded surfaces. If a renderer is pixel
based, the image is automatically exported to a 2d file format when the Export Image command
is chosen from the File menu. Vector and polygonal renderers should implement an export
callback function, which writes out the rendered graphics to a 2d file.
Function Sets