General User Interface
| Draw Lines Smoothly | Enables the OpenGL option of anti-aliasing all vectors in Houdini including the UI and the 3d viewports. You can see this immediately on the wires that connect tiles, the tile profiles, etc. See also, the Smooth Lines option on the Wireframe subtab of the Optimization tab in the Display Options window. | ||||||
| Color Pane Headers with Network Contexts | The Pane header contains the pane tab and the path gadget, which has a gray background by default. If this is option is turned on, the background color of the pane headers will be changed to their representative network type color. | ||||||
| Show Images for Image Files in File Browsers | The default value for Show Images in image-based file browsers (in the | ||||||
| Play Audio with Popup Notifications for | Enables or disables the sounds that play with message, warning, or error dialog windows. | ||||||
| File Choosers | Allows you to select a file chooser style. Note This option is only available for Macs.
| ||||||
| Startup in Desktop | Which desktop appears when Houdini starts up. By default it is Build. | ||||||
| Global UI Size | Allows you to change the Size of the UI. Changes to this parameter will take effect in your next Houdini session. |
Network Editor, Nodes, and Trees
| Center Zoom on Mouse | Scrolls the Layout Area in the Network Editor so that the tile is right beneath the mouse cursor after placement. |
| Connect Tiles with Thick Lines | Draws the lines connecting OP tiles with thicker lines. |
| Connect Tiles with Selectable Links | It allows you to click an existing link between two nodes and reconnect it by clicking on a new node. This option is turned on by default. Note If this checkbox is turned off, the ability to drag and drop nodes onto wires will be disabled. |
| Move Tiles With Their Children | If this checkbox is on, dragging a node also moves its children. However, holding Ctrl while moving a node will only move the node itself. Holding ⇧ Shift while moving the node will move it with its parents. If this checkbox is off, dragging a node will only move the node itself. However, holding Ctrl while dragging a node will move it with its children, and holding ⇧ Shift will move the node with its parents. |
| Enable Drop-on-Wire | Allows you to drag and drop a node onto a wire in the network editor to connect it in the middle of two nodes. |
| Place New tiles immediately | Places tiles immediately upon selecting an OP, instead of waiting for a second click to give the placement location of that new OP. If the Scroll to the New Tile option is enabled, Houdini will adjust the display of the Network View so the newly placed tile is within view. |
| Scroll to New Tile | Pans the Layout Area to display newly placed tiles. |
| Automatically pan when holding down Alt and dragging outside the network editor | If this option is turned on, you can hold Alt when dragging to pan the network editor around instead of dragging and dropping the node. This is useful if you want to put a node somewhere that currently isn’t visible. |
| Scale Operator Names | Enables or disables the scaling of operator names in the network editor when you zoom in and out. |
| Minimum Op Name Size | Controls the minimum size that the operator names will zoom to. This can prevent the names from disappearing into illegibility. |
| Op Name Size | The size of the operator names when no scaling has occurred. Use this as an overall scale to affect how readable the operator names are at your preferred working zoom level. |
| Maximum Op Name Size | Controls the maximum size that operator names will scale to. With the default font, values above 45 will fail. |
| Highlight the Currently Cooking Node | If enabled, then the tile that is being processed gets lit-up during when its is cooked. |
| Include Performance Statistics in Node Info | Includes performance info in the pop-up info for the tile. |
| Change SOP Render and Display Flags Separately | When enabled, when you click on a sop’s render or display flags, both of them will be set at the same time. When disabled, they will change together. |
| Display Icons in Operator Tree Views by Default | Will display OP tiles in a Tree View. |
3D Viewports
| Scene Renderer |
Tip You generally should use the highest GL version available to you. GL renderers will be removed if the driver does not support the GL version they require. The only reason you may want to downgrade is if you encountered problems with a higher GL version. The OpenGL 3.2 renderer is designed to offload much of the drawing work to the graphics hardware, and for some low-end or old OpenGL 3 hardware, this can result in very poor performance. For such hardware, use the OpenGL 2.1 renderer instead. | ||||||||
| Orientation |
| ||||||||
| Tumbling Method |
| ||||||||
| Panning Method |
| ||||||||
| Default Homing | Controls what happens when you hit the home hotkey. The default is Oblique, which has a value of 45 degrees. | ||||||||
| Wire Toggle Mode | Allows you to change the shading mode. You can also do this by pressing the W hotkey in the viewport. | ||||||||
| Delay Inactive Viewport Redraws | If this option is turned on, Houdini will delay inactive viewport redraws in the quad view. In the quad view, one section is active and the other three are inactive. When an action is done in the active viewport, it will be updated aggressively and the inactive viewports will lag behind. The inactive viewports will be redrawn once the active viewport is completely updated. Turning this option on improves performance. |
Shelf Tools and Tab Menu
| Tool History Length | The number of least recently used menu items that are kept as history in the Tab menu. | ||||||
| Tab Menu Operator Namespace Filtering | Determines which variants of the same operator are displayed in the Tab menu. The operator variants share the same base operator name but differ in scope, namespace, and/or version.
|
Takes
| Allow Auto Take Mode for Locked Assets | Allows you to edit contents of locked assets in the auto take mode, overriding the interior parameters inside the current take. Note This parameter affects the auto take mode, not takes in general. |
Animation
| Auto-Key: Add Keyframes on Parameter Change | When enabled, parameters changes are immediately processed (i.e. “cooked”), and the changes reflected in the geometry displayed in the Viewport. | ||||
| Auto-Commit: Save Parameter Change at Keyframes | When you change keyed parameters on keyframes, the new values are automatically saved as the new keyed values. You do not need to explicitly key the values. | ||||
| Set Additional First Key at Frame | Will set an extra keyframe at the specified frame (typically frame 1) when a keyframe is added. If left blank, no extra keyframes will be added. If set to '1' - it will approximate the behavior of older (pre H6) versions of Houdini, which would automatically add a key at the first frame. | ||||
| Global Set Key |
| ||||
| Default / Rotation Function | You can set the default segment interpolation function to be of the type you specify here. e.g. cubic. You can also set the default function used for rotations. | ||||
| Auto Function | Attempt to automatically determine the best function to interpolate between added keyframes. When disabled, adding keyframes inserts segments of the type specified here. | ||||
| Auto Slope | Attempt to automatically match incoming / outgoing slopes on channels. When disabled, adding keyframes will set the new segment slopes to the specified value. | ||||
| Hold Last Key | When adding keyframes in the last segment of a channel, the final segment is modified to hold it at the same value between the last keyframe and the end of the animation. Enabling this parameter allows you to insert keyframes repeatedly without changing the interpolation of the last segment. | ||||
| Enable Channel Cache | Turning on this checkbox improves display performance in the channel editor by caching channel evaluations. However, this my prevent the channel editor from updating properly when the channel is changed. | ||||
| Scope Parameters With Autoscope Enabled | Parameters of the selected node(s) which are marked as | ||||
| Open Channel Editor if Closed | If enabled, a new Channel Editor window will pop-up if there is none currently visible in the desktop. | ||||
| View Overridden Parameters in Motion view | Parameters of the selected node(s) that are currently overridden by CHOPs will be displayed in the Motion View pane. |
Rendering
| Available Render Nodes | Lists the render nodes available in Houdini that you can enable or disable.It is possible to override the preferences with the
|
| Make All Render Nodes Available in Tool Palette and Tab Menu | If enabled, all render nodes will be shown in the output driver tool palette and tab menu. Otherwise, only the subset of render nodes selected in Available Render Nodes will be shown. |
Handles
| Hide Locked Handle Parts | Keeps locked handle parts from being displayed. You will need to reload the file to take effect for existing handles. | ||||||||
| Color Transform Handles By Axis | If this option is turned on, the transform handles in the 3D viewer will display different colors depending on the axis they affect. | ||||||||
| Keep handle alignment when reselecting | If this option is turned on, the transform handles in the 3D viewer will maintain the same orientation when different objects are selected. | ||||||||
| Default Handle Alignment | Determines the initial orientation for transform handles in the 3D viewer.
| ||||||||
| Allow interior picking of Rotate Handles | If this option is turned on, you will be able to select the interior of rotation handles in the 3D viewer when no translation handles are available. Selecting the interior of the rotation handles performs rotation in all 3 axes simultaneously. | ||||||||
| Default Transform Handles to Gimbal Mode | If this option is turned on, the initial mode of rotation handles in the 3D viewer will be in Gimbal Mode. In gimbal mode, the rotation circle handles will always be aligned so that manipulating them will only affect the rotation angle of their respective axis. | ||||||||
| Default 2D Orientation Handle Transform is Global | This setting affects the orientation handles for manipulating lights and cameras. There are two ways to manipulate the handle: in local space or in global space. If this option is turned on, the default mode will be in global space. To manipulate in local space, hold down the shift key when manipulating the handle. If this setting is turned off, the default mode will be in local space, and the shift key needs to be held down for global space manipulations. | ||||||||
| Open Channel Editor If Closed When Scoping From Handles | When scoping from handles, it will open up a new Channel Editor (if one is not already open). | ||||||||
| Scope Channels When Setting Keyframes |
|
Objects and Geometry
Preferences
| Highlight Object Selections in Viewport | Provides visual feedback when objects are elected in the Viewport. | ||||||
| Automatic Parameter Folder Flipping when Picked in Viewer | Flips parameter pane folders to the folder that contains the first parameter that is referenced by any channel in the selected object if such a reference exists. | ||||||
| Default Geometry Display | Specifies the default geometry display mode of the 3D viewer. This only affects the 3D viewer in Geometry selection mode.
| ||||||
| Default Context Creation | Specifies the default context creation mode. To change it in the 3D viewer, use the icon menu in the upper-right corner.
| ||||||
| Use Existing Selection to Complete Actions | If enabled, tools use the existing selection if available to complete their actions when they are invoked. | ||||||
| Secure Selection On by Default | Enables secure selection by default - when enabled, it prevents you from losing your selection with a stray click. | ||||||
| Select Entire Subnets On by Default | When enabled, the default behavior will be to select the subnets when you select the containing node. | ||||||
| Highlight Selected Geometry in Viewport | When an object is selected, Houdini will highlight the corresponding object in the Viewport. | ||||||
| Popup Menu Selection | If this option is turned on, a menu will pop-up when clicking a spot in the 3D viewer for selecting has multiple objects to allow you to choose which one to select. When clicking on a spot in the 3D viewer for selecting has multiple objects, a menu will pop-up to allow choosing between them. | ||||||
| Keep Position when Parenting |
| ||||||
| Kinematic Override |
| ||||||
| Keep Position When Moving | If this option is turned on, moving an object will not affect the position and orientation of its child objects. This is done by modifying the child object pre-transforms and/or transform parameters. | ||||||
| Read-Only Pre-Transforms | If this option in turned on, you will not be able to manipulate objects' pre-transforms. |
SOP Caching
| Cull Level | Higher settings tell Houdini to be more aggressive at keeping the cache size down, saving memory at the expense of speed. | ||||||
| Memory Limit | The amount of memory to use to cache geometry transforms. | ||||||
| Unloading |
| ||||||
| Memory |
|
OBJ Caching
Houdini can cache object transforms for individual objects once it’s calculated them when you turn on the object’s Cache data option. This is especially useful for objects whose world space position is expensive to calculate (such as Sticky objects), and objects at the end of long parenting chains (such as Bones). This option is on by default for Sticky and Bone objects.
| Memory limit | The amount of memory to use to cache object transforms. |
| Enforce Limit | Controls whether Houdini observes the Memory limit or not. |
| Clear cache | Empties the cache immediately. |
Tip
To turn off caching on all objects without setting their individual Cache data options, set the memory limit to 0 and click Clear cache.
Tip
You can use the objcache command to manage the OBJ cache through HScript.
Particles
| Skip Particle Info Generation (Faster) | Bypasses the generation of info in the pop tiles' info pop-up
(click tile with |
Motion and Audio
| Maximum Time Slice Size (Frames) | This option allows you to limit the size of a Time Slice, expressed in frames. The default maximum is 60 frames. This is useful if you only need a few frames of history, and the Playbar is jumping ahead by large intervals. If a Time Slice is larger than this maximum size, it will be clipped from the current frame backwards (causing a gap between this slice and the previous one). The slice will always end on the current frame. |
| Enable Time Slice Flag when Creating CHOP | Sets the default behavior for when you place a CHOP in the Layout Area. All chops with Time Slice capability created while this option is on will have their Time Slice flags enabled by default. Otherwise, all chops are created with the Time Slice flag turned off. This is a convenient option to leave on when creating and working with large Time Sliced networks. This option is off by default. |
| Minimal Time Slice Cooks | Some Time Sliced chops can minimize their cooking, rather than cooking every frame. When cooking is unnecessary, or it produces the same output, these chops will stop cooking until an input changes. chops that have this feature are:
Minimal Cooking will not apply to these Time Sliced chops if they have non-constant chop inputs or time dependent chop inputs. This option is off by default. It can speed up puppeteering and chop networks that respond to isolated inputs or events. |
Compositing
Cache
| Interactive Cache Size | The size of the tile cache, in MB. If you use the compositor constantly, you should set this to a fairly large value (half the available memory for systems with more than 256Mb). This only applies to interactive applications. |
| Non-interactive Cache Size | The size of the tile cache, in MB, that is used when the compositor is not being used interactively (hbatch, hython). |
| Reduce Cache Size when Idle | In interactive applications like Houdini and Houdini Escape, when the compositor goes idle for a short time (5 minutes) it begins slowly pruning the cache down to this size. This can free up memory for use in the rest of the application. |
| Clear Cache | Clears all the compositing caches. |
Cooking
| Multi-threaded Cooking | If enabled, multi-threaded cooking is enabled. Otherwise, only 1 thread is used to cook images (the main Houdini process). |
| Threads | Specifies the number of threads to use when cooking. If set to 1, only the main Houdini thread cooks images (as if Multi-threaded cooking was off). To saturate a multiprocessing computer, use twice as many cooking threads as processors. |
| Use GPU to Assist Compositing | Allows certain COPs to be accelerated using OpenGL. Changing this preference requires a restart of Houdini. The following is a list of available accelerated operations. Operations that are greatly accelerated are marked with a *.
|
| Use Collapsible Pixel Operators | If enabled, collapsible pixel operators in series (blue COPs) will be combined into one operation. If off, they are all processed individually. |
| Tile Size | The size of the tiles. The image is divided into these tiles and processed in chunks. If you are always working at a specific resolution, you may want to specify a tile size that exactly divides the horizontal and vertical resolution. Changing this value will flush all the caches. A tile must have at least 1024 pixels in it. |
| Resolution Limit | Allows you to specify the max. size an image in the compositor is allowed to be. |
Interactive
| Cook Displayed Operators on Startup or Load | If this option is turned on, COPs that are displayed cook initially when the hip file is loaded. If this option is turned off, they will not cook and the viewport will remain black. | ||||||
| Use Fast Interactive Cooking | If enabled, the resolution of images is automatically down-scaled to a smaller resolution while an interactive edit is in progress (dragging a handle, sliding a slider or XCF slider). This gives much quicker feedback at the expense of quality. If off, the image will be cooked at normal resolution. | ||||||
| Only Use Fast Cooking On Slow Operations | If enabled, fast operations (like Bright, Gamma and Timing COPs) do not cause the interactive down-scaling of images. If off, all operations down-scale the image during user interaction. | ||||||
| Use Fast Cooking on Images Larger Than | Sets a lower resolution limit on the images that will be down-scaled during user interaction. Images smaller than this limit will not be down-scaled. In the case that the image doesn’t match the aspect ratio of this preference, the number of pixels in the images is compared and used as the limit. | ||||||
| Interactive Rendering Fraction | Specifies the down-scale factor. Smaller factors give much faster updates during interaction at the expense of image quality. | ||||||
| Cooking Feedback | Allows you to set the type of feedback which you receive while a single image is cooking:
|
Selectors
| Never Prompt for Optional Inputs | If enabled, once the minimum number of sources are connected, input selection is considered to be complete. If an Always Place option is specified, the COP will be immediately placed in its selected Viewport. |
| Never Prompt for a Generator’s Input(s) | If enabled, inputs for generators are never prompted. |
| Always Place the New COP in the Current Viewport | If enabled, once selection of all inputs is complete the COP will be placed in the current viewport without prompting for the destination viewport. |
| Always Place New Generators in a New Viewport | If enabled, generators will be added to a new viewport, if available (otherwise the current Viewport is used). If off, you will be prompted for a destination viewport. |
Names
This page allows you to customize the names of common plane
types. The default names are the first letter of the English
plane name, capitalized. These are the names that are used in
the scope fields, plane lists, VEX scripts and output Houdini
.pic files.
Colors
COPs can be colored by family type. Any new COP in that family will have its tile colored to the family color for easy identification.
| Enable COP Auto Coloring | Enables or disables this feature for all COP types. You can also individually disable family types that are not important to you. |
| Generators | The color for all generators. Because generators can take an input and generate planes 'inline' (in the middle of a network), this helps you spot where in the network planes may be created or masked. |
| Pixel Functions | The color for all Collapsible pixel operations. Because collapsible pixel operations only work when grouped together in a chain, this helps you optimize your network for these types of operations. |
| Timing | The color for all timing-related operations and non-image related operations (like merge and delete). These operations normally do not cook images or use any cache memory. This helps you track down timing changes in a large network. |
| VEX | The color for all VEX-based operations. VEX COPs have the special characteristic that all plane names matching the VEX script’s parameter names override those parameters on a per-pixel basis, so it is important to recognize these COPs. |
Cineon
This page defines the default values for all Cineon parameters
in all new File COPs and Compositor output drivers. It also
defines the cineon parameters that are used when a Cineon file
is loaded or saved outside these two contexts (like from the
Save Image... COP tile menu). Cineon files have an extension of
.cin.
| Convert from 10 bit Log | If enabled, the Cineon file is converted into linear space. Otherwise it remains in its 10 bit log space (with values from 0 - 1024). |
| LUT File | The LookUp Table file containing the 10bit cineon conversion (.lut). This file may be created manually or with the standalone icineon or ilut tools. |
| Black Point | The Cineon value (0-1023) that maps to black when converted to linear colorspace. This and the White Point and Film Gamma is used when loading Cineon files (.cin). This only has an effect if the LUT File field is empty, otherwise the LUT is used for the conversion instead. |
| White Point | The Cineon white point, which defines the Cineon value (0-1023) which represents 90% image intensity. This parameter is not used if a LUT file is specified. |
| Film Gamma | The Cineon film gamma, which defines the gamma to use in the conversion from Cineon space to linear image space (the space which the compositor operates in). This parameter is not used if a LUT file is specified. |
Scripting
| Expression Language |
| ||||||
| Parameter Fields | Entry boxes for parameters, such as those in the parameter editor. | ||||||
| Text Editors | Multiline text editors, such as those located in Edit Comments. | ||||||
| Textport | The textport.
|
Desktops and Toolbars
| Save Desktops Automatically | Changes to Panes within Desktops are saved automatically. |
| Show Hidden Files | Shows files that are marked as hidden (whose filename starts with a period). |
| Show All Files | Shows all files, regardless of what type they are. |
| Path Menu Behavior | Allows you to define the path menu behavior when you open the Desktop Manager window and use the drop-down menus to switch the Location of a desktop, instead of being prompted each time (default behavior). |
Save Options
| Save Method |
| ||||||
| Save View Commands For | This preference is helpful for reducing file bloat.
| ||||||
| Auto Save Every Minutes | Specifies the interval for the auto save feature. | ||||||
| Auto Save Method |
|
Note
You must turn on the Auto Save checkbox in the Edit menu to enable auto saving. Auto-save is automatically disabled when Houdini starts up, because it can slow down Houdini and take up a lot of disk space if it is left on unintentionally. You must manually enable it for each session.
Miscellaneous
| Restrict Web Browser to Safe Commands | Restricts the HScript commands that can be run from the Houdini embedded web browser. Turning on this option can help prevent malicious scripts from running commands through Houdini. |
| Use External Help Server | Opens the Houdini help documentation in your system’s default web browser instead of Houdini’s built-in browser. |
| Reserve Kb for the Undo System | Specifies how much memory should be used for Houdini’s Undo system - the more memory you allocate, the more Houdini can Undo. |
| Delete Channels When Reverting to Defaults | Causes the Revert to Defaults operation to delete any channels on the parameters changed by this operation. |
| Revert Invisible Parameters to Defaults | Specifies whether or not invisible parameters should be affected by a Revert to Defaults operation. |
| Make Spare Parameters for Unknown Channels | If this option is turned on, spare parameters are created to hold the values of extra parameters that are not in your version of Houdini so that you can see what changed and possibly rescue the values, rather than discarding those parameters into the bitbucket. This is useful when your hip file is from an older version or if the otl defining the node is older. However, you can turn this option off if you do not want to clutter your nodes with obsolete parameters. |
| Spare/HDA Parameter Deletion | When you are in a Type Properties and you delete one of your parameters, there might be parameters inside the asset that point to that parameter. The default is to Automatically Delete all References that are found. Automatically Delete only Simple Channel References does a more conservative job which could leave some references, but is less likely to destroy complicated expressions. Do Not Automatically Delete any References leaves dangling references, yet eliminates the possibility of expressions being affected. |
Hip File Options
| Unit Length | The length in meters of one Houdini unit. This value is used by some unit-specific DOPs parameters. |
| Unit Mass | The mass in kilograms of one Houdini unit. This value is used by some unit-specific DOPs parameters. |
Note
Unit time is always one second.
Warning Dialogs
The options in this window allow you to toggle warnings on and off. By default all of the warning dialogs are turned on.
Performance Options
| Percentage Thresholds | This setting controls the color values used to display relative cook times for node when using the performance monitor. For more information on how to use the ramp, see Ramp parameters. |