What's New in Katana 3.1

Introduction

This document describes notable changes introduced in Katana 3.1. These changes include:

• Full compatibility with the VFX Reference Platform CY2017 specification, most notably including porting the codebase to Qt 5.
• Improved support for working with very large attributes.
• Improved user interface performance.
• Improved Alembic read performance.
• An experimental new Hydra Viewer layer that shows pixels from the Monitor tab.

Technical Changes

Third-party Software

Due to the port from Qt 4 to Qt 5, the following user interface APIs have changed:

• Any Qt widget that opted in to Katana's 'key-based-dragging' protocol must be updated as follows. Previously, Katana would emit a dynamic PyQt keyBasedDragRequested signal from a widget when the user hovered the mouse over it and pressed Ctrl+B. As of Katana 3.1, your widget must instead override the customEvent() method to handle QT4Widgets.GlobalEventFilter.KeyBasedDragEvent Qt events. A widget should accept the event, and initiate a drag using a QT4Widgets.InteractiveDrag object.

• Any Qt widget that previously set a Python attribute of drawInteractiveHighlight to False should now set a boolean QObject property of the same name instead. This property allows a widget to opt out of the standard highlight effect Katana applies to a target widget of a drag-and-drop operation.

• Any Qt widget that previously set a Python attribute of STOP_GLOBAL_SCROLLING or SKIP_GLOBAL_SCROLLING should now set a boolean QObject property of the same name instead. This property allows a widget to opt out of Katana's default 'global scrolling' behaviour, initiated by holding Alt and dragging with the middle mouse button while the cursor is over a QScrollArea-based widget.

• The class UI4.Widgets.TextInfoDialog was defunct and has been removed.

Viewer API Improvements

• The Viewer API has been reworked to add support for a single OpenGL context, shared between all the Viewports. The ViewportWidget class now inherits from QWidget.

• FnViewerDelegate::getPartialXform() has been given 3 new arguments to configure which xform groups are included in the returned matrix, with the default values being consistent with existing behaviour. This change follows on from a fix made available in 3.0v2 for incorrect results when manipulating a looked-through camera with multiple transformation groups (TP 346989).

FnAttribute Improvements

local myIntAttr = Interface.GetAttr('myAttr')

local newSamples = {}
for _, sample in ipairs(myIntAttr:getSamples()) do
  -- Create a mutable copy of the sample buffer
  local buffer = sample:toArray()
  for i, elem in ipairs(buffer) do
    buffer:set(i, elem * 2)
  end

  local t = sample:getSampleTime()
  newSamples[t] = buffer
end

Interface.SetAttr('myAttr', IntAttribute(newSamples))

Performance Improvements

The performance of application startup, user interface interaction, and idle CPU usage has been improved by optimizing the Katana event system and removing instances where Katana polls for events.

The performance of Ogawa-based Alembic reads has also been improved by using memory-mapped I/O.

New Features

ProfilingMockRenderer

• A new example renderer plug-in is now shipped with Katana: ProfilingMockRenderer. The plug-in performs no rendering of pictures. Instead, its purpose is to profile Katana's scene graph expansion from the context of a renderer plug-in, implementing different traversal strategies for accessing scene graph location data. The plug-in's source code is available in plugins/Src/.

  As part of adding the ProfilingMockRenderer example, the existing Renderer Plug-ins page in the Katana Developer Guide has been split into two sections: Overview and Render API. The new plug-in is documented in a new section named Profiling Mock Renderer.

Experimental Features

Monitor Front Buffer