Rendering

FPrime's display windows are always rendering, and you can save that render at any time with a press of the "Save" button. If you want to make a print resolution render or generate an entire animated sequence, you probably want to use FPrime's non-interactive render mode. This mode is activated by the generic "FPrime Render" plugin.

When you open the Render Panel, FPrime will close any of its open windows and LightWave editors, to prevent changes in those panels from corrupting your render. It is important that you do not update objects via LightWave's Hub while rendering!

Render Panel

FPrime requires you to choose a destination filename. Frame numbers will be automatically added to this filename, though FPrime is smart and detects and reuses existing 4 digit numbers. This is useful since you can pick a previously rendered file to reuse the filename.

FPrime Render renders a range of frames. To render a single frame, use the same frame number as both start and end frame. If you are rendering a sequence of frames, you can specify a "step" to skip frames. A negative skip will render the frames in reverse order.

The exciting and interesting ability of FPrime's renderer is Progressive Refinement. This allows rendering of scenes very quickly at an initial low quality. FPrime then returns to the initial frames and efficiently adds additional work to improve the quality. By default, FPrime repeats this refinement endlessly.

As it renders, FPrime displays the current frame's quality, as well as the sequence's statistics. These quality values are not directly comparable to LightWave Antialiasing settings, but do follow the simple rule of higher numbers are higher quality.

FPrime stores extra high quality color and per-pixel statistics in two additional files per frame . These files allow FPrime to resume aborted renders as well as continue refining old renders. After each refinement pass, FPrime writes the data files to disk (overwriting the old ones), and also writes the output frame (also overwriting).

The two extra data files per frame are large, but allow the advanced progressive refinement ability, as well as the ability to stop and start rendering at any time (even in the middle of a frame). After you have finished rendering, you can safely delete the refinement files but you will no longer be able to resume the render or refine it further without starting over.

FPrime is smart about storing and using sequence quality information. You might render one or more test frames to a high quality to test the final look and antialiasing of the image. If you then start rendering the entire sequence including those frames, FPrime won't update the high quality frames until the remaining frames have "caught up" to the same quality level. FPrime uses the simple method of working on the frame that's currently at the lowest quality level.

You can instruct FPrime to Endlessly Refine, which is the default. In this mode, FPrime will continue rendering until you manually abort. Alternatively, you can set an automatic stop level by using the Stop At Level option. Finally, you can ensure that all frames have equal quality by using the Stop When All Equal selection. When Equalize mode is picked, all frames will be improved in quality until they all match the same level of refinement, then FPrime will stop. You can change the ending criteria at any time, even in the middle of rendering.

You can only refine a scene if it is unchanged since the previous render. When you start rendering and you select an existing frame, FPrime will ask if you want to replace or refine the existing images. You can press SHIFT when clicking the Render button to default to refine mode with no requester.

FPrime can also render using the classical style of defining a quality level in advance and rendering each frame until it reaches that quality level. The only big advantage of this mode is saving disk space. It also reduces the amount of repeated loading and saving to disk that the refinement mode uses.

DOF and Motion Blur

In Render mode, FPrime is able to enhance the quality of Depth of Field and Motion Blur by applying a smart "2.5D" effect that smears pixels to create blur. The effect uses 3D information about the scene to apply a 2D process, hence 2.5D. This can be very effective in reducing depth of field and motion blur artifacts when rendering only a few refinement passes. The resault is not completely correct, however, since all 2.5D effects tend to have problems with bright areas, background and horizon seams, object sillouettes, shadows, offscreen objects, and especially transparent and reflective objects. However, FPrime combines the 2.5D effect with its refinement design to automatically reduce the 2.5D "fill-in" as more 3D quality is added from more rendering refinement passes. This hybrid technique is very effective at producing decent results even at low render quality settings, eventually converging to the "true" 3D accurate result.

You can disable (or weaken) the strength of the 2.5D fillin effect by reducing the DOF and MB values found on FPrime's Master panel. Smaller values will render faster (particularly during the lowest quality, initial render passes). It is useful to lower these values (even to 0%) if you know that you will be "cooking" your render a long time for very high quality, since the 2.5D effect won't be needed or visible.

FPrime's 3D-only motion blur uses a technique that's similar to LightWave's. This produces accurate results, but with only a few refinement passes, it can show artifacts of overlapping "stuttered" shadows, reflections, and lighting. As FPrime refines more, these artifacts reduce and eventually disappear, converging to the true smooth 3D result. The 2.5D algorithm is tuned to compensate and obscure this stuttering, though it only compensates for camera and object motion, not shadows or reflections.