Display Options (3D viewer) - Houdini online help

Guides and Markers tab

Set display options for	Choose the type of geometry to apply the display options to.
Point Markers	Displays unselected geometry points in blue (unselected)/yellow (selected).
Point Numbers	Displays the index of each point in blue (unselected)/cyan (selected). Numbers start at 0.
Point Normals	If the point has a normal attribute, displays the point normal. A normal specifies the direction in which a point or surface faces. To change existing point normals, use the Point SOP.
Point UV’s (Texture Coordinates)	Displays the UV texture coordinates at each point. UV coordinates determine the placement of textures.
Point Positions (XYZ)	Displays the XYZ coordinates for each point. This option can clutter the display quickly on complex geometry. If you need it, you may want to only activate it for selected geometry (see the use of the All/Non-selected pop-up menu above).
Primitive Hulls	Displays the hulls of NURBS, Bezier surfaces, curves, and metaballs. This option is useful when there are a large number of such objects that fill the screen. Displaying hulls and hiding the actual geometry reduces the visual clutter, and speeds up the display.
Primitive Numbers	Displays the number of each primitive in violet, starting at 0. Primitives include ellipses, metaballs, tubes, meshes, particle systems, NURBS, and polygons.
Primitive Breakpoints	Displays spline edit points. This helps you build very clean skinned surfaces by minimizing isoparms by lining up edit points on the cross-sections.
Primitive Normals	Displays the normal (in pink) for primitives that have normals (primitives such as spheres, cylinders, and metaballs do not have normals).
Profile curves	Displays selected profiles (that is, profiles that are themselves selected. Profiles on selected surfaces are not automatically shown). It can be useful to turn off display of profiles after a boolean operation (for example, the Surfsect SOP) to avoid cluttering the display with profiles that appear to float in space after the trim.
Profile curve numbers	Displays the index of profile curves. The profile index is always prefixed by the primitive number of the profile’s parent surface, For example, “0.2” for the third profile of first primitive (since numbering starts at 0) in the geo detail.
Vertex Numbers	Displays the number of each vertex in violet (unselected)/pink (selected), starting at zero.
Vertex UV coords	Displays the UV texture coordinates for each vertex (if coordinates exist) in violet (unselected)/pink (selected). UV coordinates determine the placement of textures.
Vextex Grips	(Only applicable to the UV Editor.)
Filled UV backfaces	Back facing polygons in the viewport are drawn filled to distinguish them from front facing polygons.
Shading Mode	This is actually a pop-up menu that lets you choose a shading mode in which the given type of geometry will be drawn. For example, you can have normal geometry drawn smooth shaded and templated geometry drawn in wireframe.
Floating gnomon	Displays a small gnomon in the bottom left corner of the view, showing the current orientation of the world axes.
Origin gnomon	Displays a gnomon at the world-space origin (0,0,0). (See also how to display an object’s origin/pivot .)
Particle gnomon (Particle Axes / Center of Mass)	Displays gnomons at the origins of particle systems. If the particle system’s Display Particle Axes option is on, and the particles have a center of mass attribute (`com`), this will show the center of mass.
Object names/paths	Displays object names or object paths.
Video safe areas	Overlays rectangles showing the video “safe area” for picture and titles (the area in which the picture and titles (text) will be visible and undistorted on most TVs).
Field Guide	Displays a “field guide”, a traditional cell-animation tool that overlays a grid to help align elements by eye and provide points of reference between frames.
Camera mask	Controls the display of the view mask and overlay specified by the camera.
XZ, XY, and YZ Reference Planes	Displays a 20 unit by 20 unit grid on the XZ, XY, or YZ plane, centered at the origin.
Node guides	Controls the display of node guide geometry.
Node handles	Controls the display of node handles.
Follow Section mask	Controls whether the viewport automatically turns on certain display options based on the component selection type. For instance, point markers will be automatically turned on when picking points.
IK Critical zone	Controls the display of the IK critical zone guide geometry for bones.
Displayed nodes	Displays objects and geometry in the current object.
Current geometry	Displays the selected SOP in the current object when different from the display SOP
Template Geometry	Displays templated geometry.
Selectable templates	Displays nodes with the selectable template flag enabled.

Viewport tab

Name	Name of the viewport.
Type	Orthographic or Perspective.
Show Name	Displays the viewport’s name in its top left corner.
Show Camera Name	Displays the name of the camera if the viewport is looking through a camera .
Show State Name	Displays the name of the current tool (if any) in the viewport’s top right corner.
Level of Detail	Increases or decreases the display resolution of Metaballs, NURBS, and Bezier surfaces.
Aspect Ratio	Sets the ratio of width divided by height.
View Mask Opacity	When looking through a camera, there is a mask applied to the areas that aren’t going to be rendered. This option controls the opacity of that mask. For example, a very low value would display a transparent mask; a medium value would display a gray mask; and a high value would display a black mask.

Grid tab

Ortho Viewport

This tab controls the display of the grid in orthographic viewports.

Note

To show a grid in a perspective viewport, use the XZ, XY, and YZ Reference Plane buttons on the Guides and Markers tab.

Display Ortho Grid	Shows a grid in the orthographic viewport.
Grid Offset	The distance in X, Y, and Z between the grid origin and the world-space origin. Click one of the boxes between the textboxes to link the values.
Grid Spacing	The horizontal and vertical distance between grid lines. Click the box between the textboxes to link the values.
Grid Ruler	Draws every `n`th grid line thicker. Set this to 0 to not draw thicker lines. Click the box between the textboxes to link the values.

Texture Viewport

This tab controls the display of the grid in the UV texture editor viewport.

Display Reference Grid	Turning on this option displays a grid for references which divides the uv space with the spacing specified in Reference Grid Spacing.
Reference Grid Spacing	Allows you to specify the spacing of the reference grid.
Display Grid Over Image	Displays a pixel-based grid over the texture image. Use the Grid Pixel Spacing and Grid Pixel Offset options to position and scale the image grid.
Clamp Grid to Image	Prevents display of the grid outside the image boundaries.
Grid Pixel Spacing/Grid Pixel Offset	When Display Grid Over Image is on, these options control the placement and size of the grid in pixels. You can use fractional values, for example 0.5 to snap to the center of pixels. Click the boxes between textboxes to link the values.
Display Tile Boundaries	Displays a grid representing the UV boundary around the UV 0-1 tiling of the image.

Background tab

Display Background Images	Displays a bitmap image as the background for viewports. This can be useful for tracing over a sketch or reference image (rotoscoping). For more on rotoscoping in Houdini see rotoscoping and the Roto parameters in the Camera object.
Color Scheme	Choose between a light gray or black background color.

Image Source tab

Note

If the viewport is looking through a camera, the COP is automatically taken from the COP parameters on the camera object's Roto tab.This means rotoscoping is relative to the current camera that you have selected. So, if you have shots from different physical cameras, you can assign those shots to corresponding virtual cameras.

You can override the camera’s COP using the options on this tab but the next time the scene cooks it will set the COP back to the camera’s rotoscope settings.

File/COP

Choose whether the image comes from a file on disk or the output of a compositing operator (COP).

File

Filename	(File) The path to the image file to use. Click the plus icon to choose the file.
Use Res	(File) Reduces the number of pixels loaded from the source file to quickly downsample the image. A value of 1 uses the full resolution of the source image. A value of 0.5 uses half the resolution of the source image.

COP

COP	The compositing operator to use as the image source. Click the plus icon to choose the operator from the network hierarchy.
Plane	These two pop-up menus let you choose which bitmap planes to use from the compositing operator, and whether to use the alpha channel, for the background image.
Quality	Controls the fidelity of the background image. Higher values give higher quality background images but use more memory.

3D Viewport tab

Texture Mapped	Attempts to use hardware texture mapping to speed up and improve the display of textures.
Apply Zoom to Background	When this option is on, zooming in increases the size of the background image as well. When this option is off, the background image stays the same size when you zoom. This option has no effect when Automatically place image is on.
Automatically Place Image	When this option is on, Houdini automatically calculates the image offset and scale to fit the image inside the viewport. When this option is off, you can use the Image Offset and Image Scale controls to place and scale the image manually.
Image Offset/Image Scale	Manually control the placement and scale of the background image in the viewport. The Automatically Place Image checkbox must be off to use these options. A scale value of 1 retains the original size of the source image. A scale value of 0.5 would reduce the source image by half.

Texture Viewport tab

This tab only affects UV texture editor viewports.

Minimum/Maximum UV	The smallest and largest UV values display horizontally (U) and vertically (V) in the viewport. Click the box between the textboxes to link the values.
Filtered	Oversamples the background image to create a smoother, blurry look when zoomed in instead of a blocky look.

Optimization tab

Culling tab

Remove backfaces	When this option is on, Houdini does not draw primitives whose normals face away from the view (the back sides) to improve display speed. For closed geometry back sides are not normally visible, but open surfaces often have visible back-facing faces which this option will prevent Houdini from drawing. This option only applies to Gouraud shading mode .
Display Hulls Only	Displays hulls instead of the actual geometry of objects.
Visible Objects	A mask of the visible objects.
Display geometry of type	Only displays geometry of the type you select, and hides all others. Use this option to simplify the display of the scene and to help work on geometry of a certain type.
cull by drawing… primitives out of every..	Skips drawing a certain percentage of primitves to speed display.
Automatically Adjust Near/Far Planes when Homing	You can turn off this option to specify explicit near/far clipping planes that are not automatically recomputed when homing.
Near/Far Clipping Planes	Define nearest to and farthest away from the view geometry is drawn. That is, geometry closer to the view than the Near clipping plane, and farther away than the far clipping plane, is not visible.

Wireframe tab

Smooth Lines	Anti-aliases lines drawn in the viewport to create a smoother, but slightly slower display. See also, the Draw Lines Smoothly option in the General User Interface section of the Main Preferences window.
Wire Width	The thickness, in pixels, of wireframe lines.
Hidden Line Sensitivity	These two parameters allow you to work around a limitation of some OpenGL implementations that affects hidden line removal. On some OpenGLs, the lines intersect with the fill, causing the lines to appear broken. These options shift the lines in 3D to bring them in front of the fill. The left value is an offset by which the lines are shifted. The right value is an additional offset when the surface is oblique to the viewer. Most people can leave these options at 2:2 and forget about them. However, on certain machines (SGI Indy, NT Oxygen) you may have to tweak the values to prevent broken lines in hidden line display. Try adjusting the values by small increments. The setting is also affected by how much the view is dollied in/out.
Use Z Buffer in Wireframe Modes	Controls whether the z buffer is used for wire frame drawing. If this option is turned on, you can see which wires are in front of others. The option exists primarily because this creates smooth line.
Shade Open Curves in Shaded Mode	Applies lighting to open curves to make them look more like hair.

Effects tab

Shadow Sensitivity

These two parameters allow you to tweak the generation of the depth buffer for shadow maps to eliminate self-shadowing artifacts. In general, to fix self-shadowing aritfacts on surfaces that are oriented more edge-on to the light, change the first value. Change the second value for artifacts appearing on surfaces perpendicular to the direction to the light.

Interactivity tab

Interactive Mode	Use a simpler shading mode when tracking, zooming, or tumbling to improve interactivity. Choose the shading mode from the pop-up menu.
Render Time	Only switch to the simpler shading mode if the time Houdini takes to draw the view exceeds this number of milliseconds. This lets you only use the simpler shading mode when view redraw is actually slow.

Particles tab

Display particles as	Choose lines (the length of the line indicates the velocity of the particle), points, or sprites (choose a Sprite POP to specify the sprite).
Z Sort Sprites (Partial Transparency)	Sorts sprites based on their distance from the camera.
Point Size	The size in pixels of particle points.

Misc tab

Display Textures	Displays textures on geometry. Turning this option off will increase display speed.
Multi Texturing	Displays all layers of multi-layered textures. Turning this option off will increase display speed.
Projected Textures	When this option is on spotlights are represented as textured maps projected from a light. When this option is off Houdini uses GL spotlights. GL spotlights light per-vertex, so you must have very detailed geometry or the spot will appear blocky. Like Transparency, this is a multi-pass solution with one drawing pass per spotlight in the scene. This option uses texture mapping when available. Machines without hardware texture-mapping will slow noticeably. If the Light object has the Projector Map parameter set in its Shading tab, the map will be used when this option is enabled. This option does not work in conjunction with transparency or particle alpha.
Shadows	Turning this checkbox on will display shadows in the viewport. In order for this to do anything, you must have lights set up in your scene with shadows turned on. Note Displaying shadows in the viewport may slow down Houdini, since it needs to generate a shadow map for each light casting shadows.
Specular Highlights	Displays specular highlights on geometry during Gouraud shading.
Transparency	Displays transparency, including point attributes, texture pixels, or materials with alpha less than 1. Houdini does not automatically sort of geometry. You may need to sort the objects manually in the scene hierarchy list. You may also need a Sort SOP at the end of the object’s geometry chain.
Fill Selections	When this option is on, selected components are drawn filled with the selection color. You can turn this option off to be able to see an object’s texture when it is selected.
Auto Detect Attribute Type	Automatically detects the attribute type in a UV texture editor viewport using the current Display SOP.
UV Viewport Attribute Type	When Auto Detect Attribute Type is off, you can manually specify the attribute type for a UV texture editor viewport using these controls.
Scale Normal	Increases or decreases the length of displayed normals. This is useful to increase the size of normals when you are zoomed out to view a large object, or decrease the size of normals when you are zoomed in on a small object.
Thick Selected Normals	Draws normals thicker on selected objects.
Scale UV Grip	Increases or decreases the size of UV grips in a UV texture editor viewport.
Thick Selected UV Grips	Draws UV grips thicker on selected objects in a UV texture editor viewport.
Override Color Attribute	Allows you to use an attribute other than Cd as your color. For example, if you set it to temperature, you will get a false color map of your temperature attribute.

Reference Display Options (3D viewer)