I am having issues with my exports out of Blender. The frame rate seems low even though I have not touched the 24fps at all. This is true for almost all viewing cases (in the preview viewports (all options), in my ffmpeg exports, in my “view render” inside of Blender - everywhere). I cannot figure out why for the life of me.
I have a small low poly city scene with just over 100,000 faces, a camera parented to an empty that is constrained to a circle bezier around the entire scene with keyframes at 0 and 100 for a full circle motion.
Could you share screen shots of your output settings (or better the blend file - without the geometry if it would be too large)? Low frame rates in the view port could be a matter of CPU/GPU limitations, but that should not show in an ffmpeg export (given decent settings).
What worries me is that you are doing a full 360 in only 100 frames. You say a “small” city, but that does not tell much as everything is relative in 3D. Assuming an apparent size of 10 miles in diameter, the travel distance for the camera would be ~31.5 miles (pi*D) in 100 frames, or a little over 3 miles per frame (or ~5 km per frame in metric units). This may be your issue.
Thank you so much for responding! Attached is the blend file without most geometry. When I said “small city” I meant it is actually small, only 40 meters across haha
I left the base and my camera set up in the file as well. I think this all started happening when I started to mess with the graph editor - because my goal is to make one consistent video loop of this camera motion but the constraint, by default, was slowing down at the beginning and end of it’s movement around the bezier circle. My first reaction was to physically flatten the handles on the graph editor by dragging to their points but that was when I noticed the most frame rate loss. I then went back (after some research) and changed the extrapolation mode to linear (after redoing my camera set up) but I am still experiencing what seems to be a “stop motion” effect. Have no idea if the extrapolation has anything to do with this but I can only assume it has some.
Any help is truly appreciated. Thank you again for reviewing the file!
I looked at your file and did a test render (half-size, 100 frames), and it seemed OK. Your file render output was set to png so I do not know what ffmpeg settings you used. (Note: I generally output to png, and go to the Video Sequence Editor using the png files and export to ffmpeg). My standard ffmpeg settings use h.264 in mp4, high quality, keyframe interval of one half the fps (i.e., 12 for 24 fps), and max B-frames of 2. For optimal quality, I output a raw AVI file and use a standalone version of ffmpeg to combine audio and video with maximum control.
Anyway, I also noticed that your keyframes go from frame 1 (value 0) to frame 241 (value 1). In this case frame 1 and 241 would be the same so I suggest moving the key at frame 241 to frame 242. This way the loop will not have a hitch with the first and last frame being identical.
You may want to check your file’s frame rate to confirm it is what you expected. I use a utility called MediaInfo to check the settings of videos ( https://mediaarea.net/en/MediaInfo ). With it I can right click on a video file and check settings such as frame rate.
Lastly, I noticed you changed the animation duration from 100 frames (4 seconds) to 240 frames (10 seconds). This is good. I run into this every time I make a turn table animation of a model. I do not want to make a too-long animation, but I have to stop and think, “If I were to move around this object, how long would it take?” I end up increasing the length of the animation to make it seem more natural.
@Phil_n just wanted to say thank you again for even responding! I re-exported using the Video Sequencer and PNGs (with your proposed settings and tips) and it looks great.