Introduction


  • This lesson will discuss the process of composting essential V-Ray Render Elements
  • This information centers around compositing Render Elements in what is called a “Back to Beauty” comp
  • The lesson topic is approximately 20 minutes in length
  • Lesson covers all 3 Learning Cycles for the Lesson Topic – Lecture, Demonstration, and Activity

 


Contents


Overview
Available Materials
Lecture
Demonstration                                
Activity                                                                                                               


Overview


Goal - this lesson will teach you how to compose several Render Elements to get back to the beauty pass

Objective – We will composite several Render Elements and use them to create final composite in Adobe After Effects                                                            

Outcome – You will understand how to composite multiple render passes/elements back together to produce a professionally composited final image


Available materials


To set up the lesson follow the links below and download all available materials.

Lesson plan download
Presentation (Lecture) download
Demonstration tutorial download                                                                                                           
Scenes & Assets download                                      

 


Lecture



1. Terminology

a) Basic compositing of Render Elements

  • The EXR sequence is split into its component Render Elements
  • These are then stacked on top of each other using Add or Multiply blend modes to recreate the Beauty render
  • Each Render element contributes to the overall look
  • Each layer containing a Render Element can then be controlled and changed at the composite level

 

b) Compositing in After Effects

  • Ensure Adobe After Effects is set up correctly to composite 32bit floating point images
  • Make sure the rendered EXR image contains all the Render Elements needed (multi-channel EXR), or you have each render element as a separate sequence of images

 

c) Composite Render Elements in After Effects

  • Multi-channel EXR files opens as layers
  • The combined Render Elements result in a final image
  • Render Elements can be adjusted to create different effects
  • Render beauty comp as final image

 

 


2. Compositing Beauty


 

  a) Start from the back (or bottom) and move forward

  • Extract the Background Render Element from the Render_Elements.exr
    • Splitting it into a separate render element means it can be color corrected and post work done on it at composite level
    • When compositing with pre-multiplied renders, make sure to enable the UnMult option within the EXtractoR effect
    • It’s good practice to name your After Effects layer Background to help keep things straight later when there’s more copies of the EXR in the Composition

 

 

EXR render as beauty

Background Render Element

 


b) Adding Light to the Background
  • Extract the Lighting Render Element from the Render_Elements.exr
  • Contributes all the direct lighting in the scene
  • By setting its blend mode to Add this Render Element is added to the Background layer’s result
  • If the Direct lighting is slightly higher than required this can give far more head room in composite for post work
  • So changes in both intensity (by changing the layers opacity) or its color can be done far more easily at composite level

 

Background Render Element

Lighting Render Element

Combined Render Elements


c) Adding Indirect Light on Top of the Direct
  • Extract the GI Render Element from the Render_Elements.exr
  • Contributes all the Global Illumination in the scene
  • Its blend mode is set to Add to contribute the GI to the previous render elements
    • If the Global Illumination is set slightly higher than required, then this can give far more head room in composite for post work.
    • Changes in both intensity (by changing the layers opacity) or its color can be done far more easily at composite level.
    • A clean (not noisy) GI render element is always preferred as it has such a huge affect on the overall look of a scene

 

Composite up to this point

GI Render Element

Combined Render Elements


d) Time for some Reflection
  • Extract the Reflection Render Element from the Render_Elements.exr
  • Contributes all the surface Reflections in the scene to the composite
  • Its blend mode is set to Add to contribute the Reflectivity to the previous Render Elements in the composite
    • If the Reflection is set slightly higher than required, then this can give far more head room in composite for post work.  Although this is best on a case by case basis
    • Changes in both intensity (by changing the layers opacity) or its color can be done far more easily at composite level

 

Composite up to this point

Reflection Render Element

Combined Render Elements


e) Next comes some Refraction
  • Extract the Refraction Render Element from the Render_Elements.exr
  • Contributes all the surface Refractions in the scene to the composite
  • Its blend mode is set to Add to contribute the Refractions to the previous render elements in the composite
    • Allows us to fine tune the refractions in post production
    • Changes in both intensity (by changing the layers opacity) or its color can be done far more easily at composite level

 

Composite up to this point

Refraction Render Element

Combined Render Elements


f) Time to make the composite Specular
  • Extract the Specular Render Element from the Render_Elements.exr
  • Contributes all the Specularity in the scene to the composite
  • Its blend mode is set to Add to contribute the Specularity to the previous render elements in the composite
    • Changes in both intensity (by changing the layers opacity) or its color can be done far more easily at composite level
    • So a colored specular layer could be changed to another color or saturation increased or decreased for example
    • A clean (not noisy) Specular render element is always preferred as it has such a huge affect on the overall look of any scene with shiny objects

 

Composite up to this point

Specular Render Element

Combined Render Elements

 

g) Almost there when you add Atmosphere
  • Extract the Atmosphere Render Element from the Render_Elements.exr
  • Contributes the Atmosphere in the scene to the composite (including any particulate)
  • Its blend mode is set to Add to contribute the Environment Atmosphere to the previous render elements in the composite
    • Changes in both intensity (by changing the layers opacity) can be done to affect how much dense the atmosphere is visible in the composite
    • Changes to the color of the atmosphere can be done at composite level which can vastly change the look of a scene
    • While a noisy Atmosphere render element can still be used, it is a good idea to render it out as clean as possible

 

Composite up to this point

Atmosphere Render Element

Combined Render Elements

 

h) The Basic Composite
  • Each Render Element stacks on top of the other starting with the Background layer at the bottom
  • An Add blend mode is used in each case to add each render element to the result of the layers / render elements below it
  • Then come the Lighting and GI render elements to contribute the scenes lighting to the composite
  • On top of these are placed the Reflection, Refraction and Specular render elements to contribute all the reflective, refractive and shiny parts of the image
  • Finally in our basic composite the environment fog is places to provide the atmospheric effects that contribute to the overall look for the scene

 

 


i) Your first Beauty Composite
  • You have now created a very basic composite from the most common Render Elements

 

 


j) Tips
  • The effect of any layer can be lowered by turning down its opacity
    • For example:  we could reduce the effect of the specular by reducing the Specular layers opacity
  • Each Render Element layer can be color corrected independently
    • For example: The color of the Specularity could be changed from yellow to red
  • Try turning the opacity of the GI layer down to 26% and changing its color slightly using a color correction curve

 

 

Original Render

Render with tweaks to GI layer

 


 

 Dialing in the right settings

  • Set your After Effects Project’s Color Settings
    • Depth: 32 bits per channel (float)
  • Working Space: sRGB
    • Enable Linearize Working Space
  • Check EXR file’s Color Management
    • Assign Profile: sRGB
    • Interpret As Linear Light: On for 32 bpc
  • Use EXtractoR effect to select Render Element for layer’s channel
    • Enable UnMult to compensate for premultipled renders from Maya
  • All layers comped on top of the BG need to be set to Add Mode

 

 

 

 

          

      

 

 


Demonstration



Time to see it work!

Watch while I demonstrate how to composite the Render Elements together to create our Beauty pass

Demonstration tutorial

                                                                                                                                                                                                                                           

        


Activity



Time to do it yourself!

Use the provided EXR render to build our composite in After Effects