Combine single wavefront .obj objects into an animation sequence

Question

Given many .obj files that represent the 3D pose estimation for each frame of a clip, how to combine the .obj files to form an animation?

After performing 3D Pose Estimation on a single human's dance movements, I exported every frame as a .obj file. How can I combine these single .obj files back to a clip in .fbx format for example? So all that I need to do is put them sequentially one after the other, just as you do to image frames to form a video, and then I want to save the resulting animation as a .fbx file.

Thinking this should be easy with blender, I wrote a script to import all the frames inside the blender editor but once I have them inside the editor, I have no idea how to form a sequence of these frames.

I guess this should be very simple question for blender but I never used the software and it would spare time to just know what to do.

Answer 1

it seams a strange data source, however if you got it like that then so it is. Most easy would be to load all in blender, as you did, then put each in a collection and per frame enable a specific collection.

something along this :

import bpy
coll = bpy.data.collections

for c in coll:
 c.hide_render=True   #// firs hide all from render
 b = c
for c in coll:
 c.hide_render=False
 b.hide_render=True   #// HIDE PREVIOUS   

 #// render
 bpy.context.scene.render.filepath = 'pathToOutputImage'
 bpy.context.scene.render.resolution_x = w
 bpy.context.scene.render.resolution_y = h
 bpy.ops.render.render()

 b = c  #// to hide last on next itteration

to add an object into a collection. you might read this (small read) https://blenderartists.org/t/create-new-objects-directly-in-custom-collection/1289477/2

I think since you already wrote an importer hiding might even be easer and do it per object (but maybe you have more other stuff as well). Here is some more if you like to go in that direction https://b3d.interplanety.org/en/changing-objects-visibility-in-the-viewport-and-while-rendering/

in general first you hide all. if you need to loop through a collection unhide one copy the variable for the next loop to hide it on the next iteration