The playbar can show a subset of the total number of frames, allowing you to focus on a particular section of a long animation. $NFRAMES = $FEND - $FSTART + 1.įrame number of the first frame shown in the playbar. See the note about $FF and $T at the top of this section.

This is a very useful variable, especially for rendered picture filename point frame number. The current frame, (as set with the Playbar controls). $NFRAMES (the number of frames in the animation) = $FEND - $FSTART + 1.įrame number of the last frame of animation (as set with the Playbar controls). Replace $FF with $T * $FPS + 1 to fix the speed in frames per second (as set with the Playbar controls).įrame number of the first frame of animation (as set with the Playbar controls). To avoid this issue, you can use $T (floating point time in seconds) instead. This messes up double precision evaluations, but we can’t now change the evaluation of $FF without significantly breaking compatibility. To fix precision issues with floating point frames, Houdini has always adjusted the precision of $FF. If this is truncated to single precision anywhere in the pipeline, it would be rounding to something like 75.0014, which will create strobing. At frame 1800 of a long animation, the segment times will be numbers like 75.00138888888. With, say, 30 motion segments, each segment is 0.00138888 seconds. In the end you will have a working road tool inside of Unreal which can solve intersections. In this tutorial we will be combining the assets created in the previous tutorials. You can run into a precision issue when computing transforms based on the value of $FF (floating point frame number). This is the final part of the series: Complex Roads in Houdini.

Ribbon in sidefx houdini