Houdini 20.5 Copernicus

Working with Copernicus nodes

Provides next steps and workflows for how to use Copernicus nodes.

On this page

Viewing your output

You can view your Copernicus output in the Scene and Composite Viewers. Since some data is hard to visualize in the viewer, what the viewport displays isn’t always what’s in the data. Copernicus uses a default visualizer to enhance the visibility of the output.

In the Scene Viewer, there are two different levels where you can view your COP network output:

  • When viewing a node inside a COP network, the Scene View displays the first output of the COP node that has the display flag on.

    For nodes with multiple outputs, click the output name in the bottom right of the node to change which output appears in the viewer. This does not impact what outputs output in your SOP network.

    Tip

    You can also the node and choose the output name from the Flags ▸ Output for View drop-down menu.

  • When viewing a node inside the SOP network, the Scene View displays a SOP. When the COP Network node display flag is on, you're looking at a SOP that contains a COP network.

    For a COP node with the display flag on and multiple outputs in the COP network, you can use the COP Network node to control which output appears in the Scene View. In the COP Network node, turn on Single Output and then use Output to control which output appears in the Scene View. When Single Output is off, all outputs appear in the Scene View.

The Composite Viewer displays multiple views. For a COP node with the display flag on and multiple outputs in the COP network, you can use the main toolbar to choose from the output drop-down menu which output it displays.

Default COP Network settings

The COP Network and COP Network SOP control the default settings of COP nodes that don’t have their own input or settings. A node no longer uses these default settings if it has a node wired into it with values for these settings. If you unwire the nodes, the nodes return to their previous settings.

When you dive into the COP Network node, you can use the toolbar above your Copernicus network to view or change some of the following settings of the COP Network node.

  • Resolution

  • Pixel Scale (drives the Proxy 1:# parameter in the COP network toolbar)

    Note

    You can use the Proxy 1:# scale in the toolbar to cook the node resolution at a percentage of the scale. For example, turning on Proxy 1:2 cooks the nodes at half the resolution.

  • Border

  • Precision

  • Tile Visualization

    Note

    Replicates your input a set number of times. For example, set this to 3 to replicate your input three times. Tile Visualization is useful when you want to test whether your input properly tiles.

Adding files from disk in COPs

The following steps outline how you add files from disk directly in your COP network.

  1. Create a File COP in your COP network.

  2. Set File Name to the image, MP4, or EXR file you want in your scene.

  3. For files with multiple AOVs, click Add AOVs from File to specify which AOVs to bring in.

  4. Configure the File COP further for the following:

    • For MP4 files, set the Video Start Frame to the frame number from where you want the video to start playing.

    • For EXR files, update $F# ($F4 for example) in the File Name to <F#> (<F4>). This lets you set the Video Start Frame to the frame number from where you want the sequence to start playing. $F# doesn’t use the Video Start Frame.

Saving COPs

The following procedures outline how to save COP nodes in your COP network. Most COP networks require the Multiple saves approach.

Multiple saves

Follow these steps if you plan to save a COP file in your network multiple times.

  1. Create an image output node in one of the following networks:

  2. Set COP Path to the node you want to save. In a COP network, a wire attaches the node to the ROP Image Output COP.

    Tip

    In a COP network, you can also drag the node you want to save into the COP Path parameter. The parameter adds the pathname.

  3. For nodes with multiple AOVs, click Add AOVs from COP to bring in all AOVs.

  4. Under File Layout, make sure that each Port is set to the node’s AOV port you want to save out.

Single save

Follow these steps if you plan to save a COP file in your network once. This saves the COP node from the current cook.

  1. the node you want to save in your COP network.

  2. Choose Image from the Save drop-down menu. The Save As window opens.

  3. Configure your saving details and click Save.

Note

In the Composite Viewer, you can also and choose Save Frame to open the Save As window.

Referencing COP networks

Copernicus lets you bring your COP network into other networks. You can reference other COP and SOP networks while working in a COP network. You can also reference your COP network while working in a SOP network.

Bringing COPs into COPs

Follow these steps to bring another COP’s results into the current network.

  1. Create a SOP Import COP in your COP network.

  2. Dive into the SOP Import COP.

  3. Add a COP Network SOP.

  4. In the COP Network SOP, turn on Use External COP and set COP Path to the path of a node in a COP network.

  5. (Optional) Change the Output value to the desired output of the selected node.

  6. Go back up to the COP Network node.

  7. Add a Geometry to Layer COP.

  8. Wire the SOP Import COP into the Geometry to Layer COP.

  9. In the Geometry to Layer COP, set Signature to correspond to the target layer’s type.

Bringing SOPs into COPs

Follow these steps to bring a SOP network into your COP network.

  1. Create a SOP Import COP in your COP network.

  2. Configure the SOP Import COP to do one of the following:

    • Bring in an internal SOP.

      1. Dive into the SOP Import COP.

      2. Add and configure SOP nodes.

      3. Set the display flag on the SOP node you want to import.

    • Bring in an external SOP.

      1. Turn on Use External SOP.

      2. Set SOP Path to the path of a SOP node that’s outside of the COP network.

  3. If your SOP is a two-dimensional volume, do the following to turn it into a layer:

    1. Add a Geometry to Layer COP. Wire the SOP Import into this node.

    2. In the Geometry to Layer COP, set Signature to correspond to the volume’s type.

    Tip

    You can also use the Rasterize Geometry COP to take the piece of geometry and rasterize it into a layer. The node rasterizes the geometry based on the canonical camera unless you wire in a camera_ref input. To move the SOP back into view of the canonical camera, see Move SOP into image space.

Bringing COPs into SOPs

Some SOP nodes let you point to a COP network. SOPs that supported this for COP Network - Old now support this for the new COP Network. Follow these steps to bring a COP network into another SOP network.

  1. Create a Trace SOP in your SOP network.

  2. Under COP, set COP Path to the path of a node in a COP network.

    Tip

    Instead of setting COP Path, you can set File ▸ Image Input to the path of a node in a COP network. You must prefix the node’s path with op:.

Bringing COPs into LOPs for materials

You can create a Quick Surface Material LOP in your Solaris network to bring a COP network into your LOP network for use in MaterialX. See Quick Materials for how to use this LOP.

You can also use a Scene Import LOP to bring a SOP with a COP Preview Material into your LOP network.

As an alternative, you can follow these steps to bring COPs into LOPs using a Karma Material Builder subnetwork.

  1. Create a Material Library LOP in your Solaris network.

  2. Dive into the Material Library LOP.

  3. Add and dive into the Karma Material Builder subnetwork node.

  4. Add a MtlX Tiled Image VOP.

  5. Set File to the path of a node in a COP network. You must prefix the node’s path with op:. For more more information about the op: prefix, see Use data from a node instead of a file (op:).

    You can now use the COP node’s pattern and data in your MaterialX workflow.

Using COPs as materials

Follow these steps to apply COP outputs as materials on SOP (geometry) nodes.

  1. Create a COP Preview Material SOP in your SOP network.

    Tip

    In the Copernicus network, you can instead use the Preview Material COP and wire your nodes into the different inputs to test how the materials display.

  2. Wire the SOP on which you want to add materials into the COP Preview Material SOP.

  3. Go to Material ▸ Base in the COP Preview Material SOP.

  4. Under Base Color, set Source to COP.

  5. Set Base Color COP to the path of a node in a COP network.

  6. (Optional) To render your geometry with the materials applied, go to /stage and add a Scene Import (All) LOP. This brings in your geometry so you can render it using Karma.

Copernicus

Basics

Next steps

  • Working with Copernicus nodes

    Provides next steps and workflows for how to use Copernicus nodes.

  • Slap comp

    Slap composite (slap comp) is a fast image manipulation you can use to view approximate and live results of a final composite.

  • OpenFX

    Describes what OpenFX is and how to use it in your network.

  • Hatching

    Describes how to use hatching in your Copernicus network.

  • How to use ONNX Inference

    Describes how to apply inference using a model in the ONNX Inference node.

  • Copernicus tips

    Useful tips and information while using COPs.

Advanced concepts

  • Normals

    Defines the normals that the Copernicus network uses.

  • Spaces

    Defines the spaces that the Copernicus network uses.