Houdini 20.5 Solaris and Karma

Solaris scene viewer

Describes the differences/enhancements in the Solaris viewer compared to the Houdini object/SOP viewer.

On this page

Viewport options menu

  • In the viewport options menu you can choose the render delegate to use to render each viewport (below the Set View submenu).

  • In the Set View submenu you can set a viewport in a split view to “Image”, which shows a rendered image of the scene.

  • The UV viewport type is not available.

Display options

To open the Display Options, click the button in the display toolbar to the right of the viewport, or move the mouse pointer over the viewport and press D.

  • The Render tab in the display options contains render delegate-specific options.

  • On the Guides tab, you can show the render time and render stats from the render delegate.

Lighting overrides

By default the viewport reflects the lights found in the scene. If no lights are found, Hydra produces a head light. The head light type can be a distant light along the camera view or dome light. Along the right side of the viewport are buttons to override the scene lights.

  • Available lighting modes change based on the chosen render delegate.

  • Disable Lighting disables all scene lights, in order to visualize emissive shaders. With the Houdini Viewport, it produces an unlit appearance.

  • The automatic dome light is a uniform white color. A map can be applied using the HOUDINI_DEFAULT_DOMELIGHT_TEXTURE environment variable.

Render delegates

USD uses a generic rendering interface called Hydra. As long as a third party viewer or renderer implements the Hydra API, Houdini can use it to render the USD stage in the Solaris view.

  • By default, you can choose between the native Houdini GL view and the new Karma renderer.

  • If you have other Hydra delegates (for example, Pixar’s RenderMan and Storm GL delegates) installed where Houdini can find them, they will appear in the viewport options menu.

Tip

You need to make sure the render delegate is found by the USD plug-in search, using the PXR_PLUGINPATH_NAME environment variable.

You can also set the environment variable TF_DEBUG to PLUG_*, which causes the USD library to print out useful information as it scans for and loads plug-ins.

Solaris and Karma

USD

Geometry

  • SOP Geometry I/O

    Details of how Houdini converts SOP geometry to USD, and how you can control the process.

  • Component Builder

    The Component Builder tool puts down a network snippet for creating a USD model from SOPs, with support for materials, variants, payloads, and layering.

Layout

  • Stage Manager

    How to work with the Solaris stage effectively.

  • Edit node

    Interactively transforms prims in the viewer. Can use physics collisions to position props realistically.

  • Layout node

    Provides tools for populating a scene with instanced USD assets. You can place individual components, paint/scatter components in different ways using customizable brushes, and edit existing instances.

  • Custom Layout Brushes

    How to create layout brush digital assets you can use to customize the behavior of the Layout LOP.

Look Development

  • MaterialX

    Houdini has VOP node equivalents of the MaterialX shader nodes. You can build a shader network using these nodes, or import an existing MaterialX-based shader, and use them with Karma (Houdini’s USD renderer).

  • UDIM paths

    You can encode different tiles of a texture space into different texture files, each with its own resolution. You can then specify a texture filename such as kaiju.exr, and Houdini will replace the token with the specific tile address at load time.

  • Shader translation framework

    Describes the Solaris shading framework, including shader node translation to USD primitives.

Karma User Guide

Karma basics and workflows