Gaffer: Tessellation and More [Addendum 1] (Patreon)

Welcome to the first supplement to my Introduction to Gaffer series! There are a few topics I wanted to cover: a new node, some light editor tips and denoising. Let's get started!

MeshTessellate

This node was added to Gaffer 1.4 to provide a way to manage the subdivision level/resolution of meshes natively in Gaffer. It's an alternative to Cycles' Subdivision Max Level parameter. MeshTessellate should provide better performance and more stability. You can set it up by connecting the node and adding a path filter to the geometry you want to tessellate.

In the old Cycles workflow each subdivision level increases the number of polygons by a factor of 4. Tessellation works a bit differently: the Divisions parameter sets how many times each edge is divided. This means that MeshTessellate Divisions will often be much more than the equivalent Cycles Max Level. For example, on a simple plane (1x1) a subdivision level of 9 would mean 262,144 quads, equating to tesselation divisions of around 350 (246,402 triangles). Obviously these are not directly comparable, but it shows in general how many more divisions are needed. You'll need to experiment to find the best settings for your scene.

You'll also want to enable Calculate Normals for a nice smooth mesh.

Light Editor

When working in a Catalogue you might wonder how to access the convenience of the Light Editor while refining your renders. At first glance it appears that you need to have the main node graph focused for the Light Editor to show the lights in the scene. This is because the default behavior is to show the focused node (and everything upstream from it). There is nothing upstream from a Catalogue, hence an empty Light Editor.

You can change this by clicking the Editor Focus button in the upper right of the pane and setting it to Node Selection.

This way you can have your Catalogue focused and then click on any other node in the graph and the Light Editor will show all your lights. You can also Pin the Light Editor to its current state so that no matter what else you click on it will remain unchanged. This workflow applies to all panes in the interface.

Cycles Denoising

The CyclesOptions node shows some denoising settings, but enabling them doesn't seem to have any effect. To get things working you'll need to add a boolean parameter called denoise to your Outputs node.

This works for both batch and interactive renders. In order to view the denoised result from a Catalogue select the denoised AOV.