Jump to content

Why is the same frame never the same?

Recommended Posts



I'm currently going through Marijn Raeven's tutorial on Natural Environments from HelloLuxx. It is only for still images, not animation.


However, I can't understand why, when I render exactly the same frame, immediately after it has rendered once, that it's different?


In the scene there's a stream so has a texture with a simple noise bump and then some roughness, specular (Beckmann) and fresnel in the reflectance channel. It also uses the Physical Sky. On rendering, I just render out a section of the stream and the specular highlights are never in the same place - when A/Bing the two images in the Picture Viewer, they jump, even if slightly.


This is with and without GI... with both the Physical and Standard renderer, even on very high settings.


If someone gives me an algorithm of, say x = a + b / 2 where a=5 and b=3, then the answer is always x=4. Never x=3.8 or 4.2 or whatever - so why, when a rendered calculates, it come up with small differences each time?


Are the built in renderers not up to this kind of job? I was reading through a greyscalegorilla article and someone commented "You should add one more con for Physical, Flickers in animation!!!!" Or do some settings have to be cranked way up so each frame will take an hour or more?


Thank you for your help



Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.



C4D Cafe is the largest CINEMA 4D community. We provide facilities for discussion, showcasing and learning our favorite software :) Register now to gain access to all of our features. Once registered and logged in, you will be able to create topics, post replies to existing threads, get your own private messenger, post status updates, manage your profile and much more. If you need to find solution to your problem or otherwise ask for help, Cafe is the right place.
  • Create New...