Davide WLaVidaLoca Mella


About Me

VFX Artist


Recent Forum Posts

Export Animated gif with Image Magick and FFMPEG TOP nodes 2020年4月11日2:08

Hello from 2020!
in the era of ImageMagick and FFmpeg integrated in Houdini's TOP, generating our beloved gif should be pretty straight forward.

But, there is something I must be missing.
I am not able to export gif correctly neither using FFMpeg Encode Video TOP nor ImageMagick.

Could you please point me in the right direction?
Below some test and results of my research


1A - gif from image sequence (ROP fetch > IM gif)
2A - gif from mp4 ( rop fetch > ffmpeg to mp4 > IM to gif)

1A - gif is created but seems like the frames are overwriting each other rather than appending in sequence
tried with output file tag file/video and file/image
2A - errors: there are no input images


Getting these errors in the log:
Codec AVOption apply_trc (color transfer characteristics to apply to EXR linear input) specified for input file #0 ([i]"path to framelist"[/i]) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some decoder which was not actually used for any stream.

GIF muxer supports only a single video GIF stream.
Could not write header for output file #0 (incorrect codec parameters ?): Invalid argument
Error initializing output stream 0:0 -- 
Conversion failed!

Conversation about animated gif:

https://www.sidefx.com/forum/topic/46690/# [www.sidefx.com]

Mestela's Tokeru on ImageMagick and FFMPEG commands:
http://www.tokeru.com/cgwiki/index.php?title=GeneralUtilties#Gifs [www.tokeru.com]
(I have tried these in the command line of IM / FFMPEG tops, no luck)

https://forums.odforce.net/topic/33138-some-looping-rnd-animations/?do=findComment&comment=191821 [forums.odforce.net]
iFightForTheUser posted this code for FFMPEG:

    for ARG in $@; do
        ffmpeg -y -i $file -vf fps=10,scale=500:-1:flags=lanczos,palettegen $palette
        ffmpeg    -i $file -i $palette -filter_complex "fps=10,scale=500:-1:flags=lanczos[x];[x][1:v]paletteuse" $file_name.gif

not sure how to implement this correctly in the command line.

I am having trouble sending a hip file atm, will do asap if helpful.
TAGs: export animated gif from houdini using ffmpeg image magick TOP PDG nodes. gif conversion. gif output.

find degrees between 2 vectors 2020年3月29日6:49

In case is helpful..

If you want the rotation value in degrees for each axis component.

vector v0 = normalize(set(-1,0,-1));
vector vref = set(0,0,-1);

vector4 orient = dihedral(v0, vref);
vector angle = qconvert(orient);

angle = degrees(angle)*-1;
v@angle = angle;

You could reference the angle attribute in the rotation parameter of a transformSOP.

tag: rotation in degree for each axis component from direction vectors

RBD Material Fracture issue: How to sperate the inside outside group after adding edge detial for the hires geo? 2018年12月3日2:27

inside group works well with production build .416
outside group seems to just include all the primitives.

in the meantime “!inside” will do the trick.