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I've tried the particle system to generate a star field and it works fine for single frame renders. Now I'm working on a 10 second film logo splash and I cannot get the star field to remain static while the camera moves. I've searched and read many posts including a prior posts here about baking but I cannot figure out how to grab a single frame instance of the falling particle objects and make it static for a full 10 vid.

I have gotten a static field but the mesh is in the way and I cannot see through the object, just the outside and the emitted objects on the outside of the mesh. When I move the mesh with key frames the star field moves also. Any ideas.

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2 Answers 2

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I have gotten a static field but the mesh is in the way and I cannot see through the object, ...

To hide the emitter uncheck the Emitter option in the render panel:
render option

Unfortunatley it is not possible to fully freeze the physic simulation. The minimum timestep is 0.001/frame.

If you're using objects for your particles you can press CTRLSHIFTA or search Make Duplicates Real from the search menu (SPACE in the viewport) to create static duplicates.

If you're not using objects you could still

  1. Create an object with a single vertex at (0.0,0.0,0.0) and use it for the particles.
  2. Duplicate these vertices with CTRLSHIFTA
  3. Apply a halo material to the single vertex object and remove the particle system.

To simpify this, you may use this script

import bpy
#creates a mesh object
#from the selected particle system
#from the current frame

obj=bpy.context.active_object

ps=obj.particle_systems[0]

count=0
for pl in ps.particles:
    if pl.alive_state=='ALIVE':
        count+=1

mesh=bpy.data.meshes.new('point_cloud')
mesh.vertices.add(count)

for i in range(count):
    mesh.vertices[i].co=ps.particles[i].location

dupli=bpy.data.objects.new('point_cloud',mesh)
bpy.context.scene.objects.link(dupli)

You could also write the cache to disk by enabling the option Disk Cache in the Cache panel and baking the simulation afterwards. With the default options a folder named blendcache_blendname will be created in the folder where the .blend-file is located.

In this folder the data for each frame is stored. The template/scheme is filename_frame_subframe. Just copy your frame you want to be frozen and replace the following frames. The amount of particles should be constant in this time period. No particle should be born or die.

Afterwards enable the External option and choose blendcache_blendname as folder and filename as filename.

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You could render the starfield and use this image as a background image for your animation.

Select the world tab and tick Paper Sky

enter image description here

Create a World texture with the highlighted settings:

enter image description here

Tutorial: Rendering with a Background Image

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