Is there a way to render only between two frames numbers? (e.g. between frame 201 and frame 504). Last night I was rendering out at 4K and it work great for the first 500 frames but it crash (I think a memory error) I just want to render just the remain frames. Thanks.
There is no Repair function currently.
You can however generate part of the video, by selecting the start and end time in the dialog box.
This is not perfect because
- you need to calculate the time from the frame rate and the frame number where you want to start from
- You have to make sure the VRay settings are exactly the same
- You need to find a way to stitch the two videos
Be very careful when calculating the start/end times, as @Fredo6 mentioned. I don’t think Animator accepts high-precision numeric time values (e.g., 20.333 seconds would be rounded to 20.3 seconds or something similar). When I ask for rendering a restricted time span as a clip, I only specify the start/end times to 0.5 second resolution, which Animator definitly uses. For that reason, I usually choose frame rates where a half-second can be exactly represented as the boundary between adjacent frames, such as 24 FPS. If you choose a frame rate such as 25 FPS and render time spans at 0.5-second resolution, then the frames will start and/or end in between what would have been regular 25 FPS cadence. This can cause twitches if there is movement in the scene across the start or end boundary.
For example, if you use 25 FPS and render the time span 2.5 to 3 seconds as a clip, the first frame in that clip will fall in between what would have been frames 62 and 63 (approximately) in a full 0 to 3 seconds clip. If you use a video editor to drop the 2.5-3 second clip onto the last half second of a full 0-3 clip, any animation (camera, objects, etc.) will have a stutter at the junction.
Thank you, very helpful information. I did another test last night and it rendered all the frames this time but when it came time to create the video from images using FFmpeg the video was just black (I watched the memory usage for the first hour and it was up about +20 GB). Next, I will try to render smaller blocks of images (400-500 frames each night) and combine them all to a single folder and run FFmpeg with a command line. Now I just need to work out the command line This should be possible?
Did you ask Animator to save the raw individual frames? If so, are they solid black if you look at them? If you haven’t tried examining the raw image frames, I suggest rendering a 1-second clip from somewhere in the overall animation and have Animator save the individual image frames. Then you can look at them with an image viewer to see if they are solid black or not.
Regarding how to invoke ffmpeg manually to convert a series of still image frames into a movie, here is official documentation. Here is an example of how I did it a couple of years ago or so (executed on a Mac, but the ffmpeg switches are probably the same if you have a similar version of ffmpeg to what I was using):
/Applications/ffmpeg -i average%d.png -vf "fps=25,format=yuv420p" out.mp4
-i switch’s parameter
average%d.png is a pattern-match expression that will match any file (in the current directory) who’s name begins with “average” and then has a sequence of decimal digit characters, and who’s file type or extension is “.png”. You can adjust the pattern expression to suit your situation. The parameter for the
-vf switch can specify a wide range of properties. In my example, it sets the frame rate to be 25 frames per second, and the format to yuv420p which is a common video encoding format. The final output is written as an MPEG4 (MP4) video container file.
Again, thanks for your help. I just happen to look at the raw individual image frames before rendering that video and they were not black. However, I did notice that RAM usage was down to under 2GB, after dropping down from +30GB. I think there was a memory error, that why it just render a black video. I rebooted my PC and run a 1-second clip test and I worked Ok. I think I will try next just rendering 10-second clips and combine them all to a single folder and run FFmpeg.