Baking Final Gather

Maya, Mental Ray: Lighting

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This page covers the baking of final gather in scenes where the camera’s may be moving but the lighting and models are static.

Baking FG is great for two reasons.

1. Eliminates FG Flicker
2. Improves Render Times

A knowledge of Final Gather is required on this page, so please see the page “Understanding Sampling and Final Gather” for a grounding on this topic.

One problem with this method is that we are restricted to moving cameras only. Moving props characters and or lights can potentially break the bake. But there is a workflow for working around this, though it requires more setup, see section 3.

1. Setting up the scene
2. Baking Final Gather (moving cameras only)
3. Moving Props, Lights and Characters

* Title image by student Jay Tarquin based on the photo ‘Still Life’ by Anatoly Che ©.

This Page Is Beta: Temp vids and some content may not match.

Contents (38 mins)

1.1 – Scene Setup
1.2 – Linear Workflow
1.3 – Setting Exposure
2.1 – FG Flicker Explained
2.2 – Baking FG
3.1 – Indirect and Direct
3.2 – Animated Character Probs
3.3 – Background Rendering
3.4 – Foreground Rendering

Instructor

Andrew Silke

Last Updated

October 2015

1. Introduction (6:43 mins)

This section covers the modelling and light setup of the scene including the setup of linear workflow using our custom MR shelf. Please note this requires a knowledge of “linear workflow” so see that page for more details.

We’ll also expose the camera to let more light in using a photographic lens shader mapped to the camera.

1. Scene Setup
2. Setting Up Linear Workflow
3. Exposing the Camera

If you’re familiar with all of these concepts you can skip to Section 2.

VIDEO 1.1 : SCENE SETUP: MODELLING (1:34 mins)

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Scene setup and modelling
VIDEO 1.2 : SETTING UP LINEAR WORKFLOW (2:39 mins)

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Setting up linear workflow with the MR Shelf.
VIDEO 1.3 : EXPOSING THE CAMERA LENS (2:30 mins)

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Setting the exposure with a lens shader
2. Baking Final Gather (11 mins)

In this section we’ll find out why final gather will flicker in moving scenes and how to bake it to remove this from happening.

1. Final Gather Flicker Explained
2. Baking Final gather

The eyes can follow an aim control or rotate locally to the head or in world.

Drag and drop the rig into your scene, setup the pivots and hide the placer control. Adjust the settings and skin as desired. This rig also comes ready for correctives which are the additive result of the follows and blinks combined.

VIDEO 2.1 : FINAL GATHER FLICKER/BUZZ EXPLAINED (4:09 mins)

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Final Gather Flicker
VIDEO 2.2 : BAKING FINAL GATHER (7:45 mins)

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Baking Final Gather
3. Using FG In Combination With Moving Props and Characters (19 mins)

This section will start to cover mixing FG baking with moving characters and props. Moving objects in the scene or moving lights won’t sit well with FG baking. But is is still possible to bake backgrounds with a big speed improvement and reduction of flicker. There’s just a few things we need to understand first.

VIDEO 3.1 : INDIRECT AND DIRECT LIGHT: BAKING FG VS LIGHTS (4:43 mins)

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Final Gather Flicker
VIDEO 3.2 : PROBLEMS REGARDING ANIMATED CHARACTERS (1:37 mins)

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This Page Is from an old series that I’ve spliced in here. This video is temporary
VIDEO 3.3 : SOLUTIONS TO ANIMATED CHARACTERS: RENDERING THE BACKGROUND (8:34 mins)

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This Page Is from an old series that I’ve spliced in here. This video is temporary
1. Get it all working in a master layer

2. Duplicate masterLayer into BG layer.

3. Click off “render” for the master layer render icon

4. BG Layer FG setup
a) Enable Map Visualizer (this is optional but just for you)
b) Rebuild On
c) rename default.fgmap to bg.fgmap (do this early)
d) hide the character and moving props
f) First Frame Render
g) Rebuild Off – Subsequent Frames – Rebuild Freeze – After Final Frame
FG has been baked now, that’s it, done.

5. Prepare character shadows for BG render layer
a) switch character visibility back on
b) Layer Override – Primary Visibility Off on Animated Geo, File Name Prefix (BG) (doesn’t need layer override actually, just set the attributes)

6. Batch Render BG Scene
Save file and render the background render layer as a separate batch render on the farm. This way we won’t mess with FG baking with Layer overrides as I don’t trust.
720p/0.75 quality (quality is up to you) be sure to switch Quality > Framebuffer back to 16 bit (32 bit is overkill and much larger filesizes)

7. Save a new maya file for FG setup

8. Prepare foreground render pass
a) Duplicate masterLayer into Foreground layer.
b) Rebuild change to “on”
c) default.fgmap or I’d change it to foreground.fgmap (just to be safe)
d) Layer Override – Primary Visibility off on BG Geo, File Name Prefix (FG) (doesn’t need layer override actually, just set the attributes)
e) Final Gather Mode – Optimize for Animation
f) Physical Sun and Sky – ensure Use Background is ticked
g) Untick Master Layer for rendering (Don’t render, should be off already)

9. Batch Render Foreground Scene
720p/0.75 quality (quality is up to you) be sure to switch Quality > Framebuffer back to 16 bit (32 bit is overkill and much larger filesizes)

10. Comp in AE

VIDEO 3.4 : RENDERING THE FOREGROUND (4:57 mins)

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This Page Is from an old series that I’ve spliced in here. This video is temporary

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