Render Preview First - enabled


If Render Preview First is enabled at a job, then RR renders a few frames of the job first.

Preview renderings have automatically a higher priority than the main render phase (default config: +20 ).


The Preview Render is very useful if you have many jobs.

After the previews are finished you...

  • ...have an overview how long all yout jobs will take to render.
  • ...can view all the pictures at the local website.
  • ...have a quick overview if one of your render jobs is crap 
        (e.g. wrong light is hidden, wrong shader assigned, texture not found). 



It is especially useful for overnight renders:

Example: 

Artists sends 27 jobs at 17:00.

RR renders 8 frames (or less or more as configured) of all jobs.

At 17:30 the artist can view these frames and check for errors.

And then he drives home and knows all jobs will be right tomorrow morning.



Render Preview First - disabled


On the other side, if you disable Preview Render you need to make sure that...

  • ...frame render times in high quality are reasonable.
      (you get everything rendered until tomorrow/deadline/next scenes have to render)
  • ...you have setup not made any mistake in your scene.
       (helper objects still visible,  passes/layer visibility setup is right, no local textures used)
  • ...shader/plugins are installed on the farm



Yes, these are simple things to remember.
And you are doing them probably for years now.

They do not sound very problematic and they usally do not happen. 
Exspecially if you have rendered the scene before.

But I personally know from my and others experiences that they do happen.
And especially if the deadline is tomorrow, you are in a rush and have not slept enough.
And because the deadline is tomorrow, you must not have any issue with your render.

This is why I implemented this feature. That these mistakes do not happen (again):

  • You add an object and forget a visibility or shader setting for a pass/layer. 
    A whole night of render for nothing.
  • You are tweaking lights and shaders.
    Therefore you disable hair or particle simulations in a differnt part of the scene to be able to work faster.
  • You tweak shaders/lighting in your scene and it does not take that much more time. 
    But at render stage some models are replaced with highres-versions   or   your render settings (DOF, Mblur) are different, 
    render times rise by hours...
  • You test the render times and they are good, but in the middle of the sequence is a small part where the camera moves close to a small object. 
    And this "usally small" object has a frosted reflection/refraction and your whole scene is visible in the reflection... 


As you can see rendering the preview first has advantages. 
You can disable it (I also do it sometimes), but then the job should be a fast light-weight render job that you have already rendered some times.




Render Preview First - with approval


There is another feature that you can combine with Render Preview First.
You may enable the job option Require Approval After Preview as well.

In this case RR renders the preview frames and the job is disabled until you approve the Preview Frames via rrControl.


Note that there is a user right for the approval command (rrConfig, menu server, tab rrLogins).

You may remove the user right to approve jobs for everybody (user *anonymous* ) and allow it for some render wranglers/supervisors only.
Or add some trainee user as rrLogins and remove the right for his user only.



Words at last


Exspecially if the deadline is near and you are thinking of disabling the render preview (as you could perhaps can save a small percentage of scene load time), 
jobs that render wrong jeopardize the deadline. 
And you usally make more of these small mistakes the more you have to hurry.