Reference Display Options (3D viewer)

Displays unselected geometry points in blue (unselected) or yellow (selected).

Displays the index of each point in blue (unselected) or yellow (selected). Numbers start at 0.

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.

Displays the UV texture coordinates at each point. UV coordinates determine the placement of textures.

Displays the XYZ coordinates for each point. This option can clutter the display quickly on complex geometry. Consider using one of the visibility options to reduce the number of positions displayed.

Displays velocity vectors for a point attribute named v. This will show where a point will be in 1 second at the current velocity. This is scaled by the Normal Scale (Geometry page).

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.

Displays the number of each primitive in violet, starting at 0. Primitives include ellipses, metaballs, tubes, meshes, particle systems, NURBS, and polygons.

Displays spline edit points. This helps you build very clean skinned surfaces by minimizing isoparms by lining up edit points on the cross-sections.

Displays the normal (in pink) for primitives that have normals (primitives such as spheres, cylinders, and metaballs do not have normals).

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.

Displays the index of profile curves on NURBS surfaces, starting at zero.

Displays markers for vertices. These are slightly offset into each polygon to show distinct vertex selections. When unselected, they appear as hollow squares, and are filled in when selected.

Displays the number of each vertex in green (unselected) or yellow (selected), starting at zero. Each polygon has a slightly different shade of green to help differentiate them.

Displays the vertex normals, if they are present in the geometry. Each normal is slightly offset into the polygon to which it belongs. Each primitive colors its normals in the same shade of green, but primitives vary the shade slightly to help group vertex normals.

Displays the UV texture coordinates for each vertex (if coordinates exist) in violet (unselected) or yellow (selected). UV coordinates determine the placement of textures.

(Only applicable to the UV Editor.)

Back facing polygons in the viewport are drawn filled to distinguish them from front facing polygons.

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.

When enabled, the shading mode cannot be changed by the viewport shading menu or the wireframe toggle. Template and Current Model display sets are locked by default to avoid becoming shaded.

Ignore Cd (color) when drawing the objects belonging to this display set. Template and Current Model display sets are faded by default. This option allows the displayed geometry to be less prominent when Cd is present.

X-Ray geometry will display as wireframe when behind other objects. This is off by default in all display sets.

When enabled, lighting is enabled for all geometry belonging to this display set. When disabled, it acts like the viewport’s No Lighting setting. This will override the viewport’s lighting selection.

Creates a new display option which is used by custom rendering hooks. They are not visible unless a rendering hook uses it to display something. They have no effect in an unextended Houdini session.

Create a new text display option, which displays the value of a geometry attribute as text (ie, 10, 1.2 0.6 -2.3, /shop/decal1). It is located at the point position, vertex position or primitive centroid, depending on the attribute’s type.

Create a new vector display option, which displays the value of the attribute as a 1,2 or 3 dimensional vector. The vector originates from the point position, vertex position or primitive centroid, depending on the attribute’s type.

Increases or decreases the display resolution of Metaballs, NURBS, and Bezier surfaces.

Fixes concave polygons by tessellating them to triangles so they appear the correct shape. When disabled, concave polygons may not appear correctly, but geometry will update faster. This can be disabled if models are known to have only convex polygons. (A concave polygon has one or more 'bites' taken out of it).

When enabled, the Instance object (and any other objects with the proper instancing parameters set on them) will do point instancing in OpenGL.

This copies the reference geometry to each point of the instance geometry with some variation in each. To increase performance, a percentage parameter is available to cut down on the number of displayed instances by only instancing a percentage of the total points.

The thickness, in pixels, of wireframe lines.

These two parameters allow you to work around a limitation of some OpenGL implementations that affects hidden line removal and wire-over-shaded modes. In some instances the lines are so close in depth with the surface that they appear broken. These options deepen the surface in 3D to bring them in front of the fill. The left value is a variable offset that changes based on the angle of the surface to the viewer (zero when perpendicular). The right value is a constant offset by which the surface is shifted.

Most people can leave these options at 2,0 and forget about them. However, with some graphics hardware, the values may need tweaking 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. This is mapped directly to the OpenGL polygon offset values.

Applies lighting to open curves to make them look more like hair.

Choose lines (the length of the line indicates the velocity of the particle) or points.

Draw particles that qualify as sprites as sprites (choose a Sprite POP to specify the sprite). A particle must have one of the spriteshop, spriterot or spritescale attributes present to be considered a sprite.

The size, in pixels, of particle points.

The size, in Houdini units, of the discs.

Turning this on will orient discs to normals. If there are no normals, it will orient to velocity.

The minimum and maximum display size of a sprite texture.

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.

Increases or decreases the size of UV grips in a UV texture editor viewport.

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.

Packs the attribute’s values into the visible color spectrum by mapping the minimum and maximum attribute values specified to black and white. This makes it easy to visualize an attribute with a value range of 0 to 100, for example.

Displays the viewport’s name in its top left corner.

Displays the name of the camera if the viewport is looking through a camera.

Displays the name of the current tool (if any) in the viewport’s top right corner.

You can specify which clip planes are adjusted when a home is done, none, either one or both. This allows you to explicitly set near or far clipping planes that are not automatically recomputed when homing.

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.

Due to GPU Z-buffering issues, the far/near ratio will never be more than one million. If a larger range is selected, the near clip plane will be moved out into the scene until a one million far/near ratio is achieved.

This value prevents homing from zooming in too far, which can happen if the geometry is very small (like a single point). Instead, treat small geometry as if it had this minimum size. The value is in Houdini world units.

Sets the ratio of width divided by height.

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.

Allows you to choose the display mode of stereo images in MPlay. You can choose between Anaglyph, Horizontal Interlace, or Horizontal Interlace (Reverse).

Automatically detects the attribute type in a UV texture editor viewport.

When Auto Detect Attribute Type is off, you can manually specify the attribute type for a UV texture editor viewport using these controls.

Applies gamma correction to the beauty pass of the viewport, which contains only user-generated geometry. Guides, handles and other visual aids are not affected.

Applies a LookUp Table (LUT) to the beauty pass, after gamma is applied.

The gamma correction and LUT are applied to the background image in addition to the beauty pass.

Enables high-quality display of the viewport by smoothing jagged edges of lines and polygons. Increasing this setting will proportionately increase the amount of framebuffer memory used. 4x and 8x modes should only be used if the graphics memory installed on the graphics card is 1GiB or higher.

Removes jagged edges of lines from wireframe models and guides with a smaller performance hit than using Scene Antialiasing. See also, the Draw Lines Smoothly option in the General User Interface section of the Houdini Preferences window.

Enables High Dynamic Range (HDR) rendering which produces higher quality results for volumes and transparency. It can also be used in

superwhite values. If enabled, HDR images are render to flipbooks. Enabling this option doubles the framebuffer size.

Draw objects with per-pixel alpha, texture maps with alpha or material transparency using alpha blending (via an over operation). When off, pixels with non-zero alpha are drawn and zero alpha pixels are discarded. The quality of the transparency can also be selected, with the higher quality options impacting performance.

When this option is on, selected components are drawn filled with the selection color when in Smooth Wire Shaded display mode. You can turn this option off to see an object’s shading clearly when components are selected.

Direct lighting of the surface by normals.

The global ambient light of the scene.

The shiny highlight, which is colored but the light, not the surface.

Glowing objects.

The number of samples to use when rendering area and environment lights in High Quality Light Shading mode. It is ignored when this mode is not active. Higher numbers produce more accurate results, at a slight performance hit.

Enable Screen-space Ambient Occlusion, which shadows objects based on the amount of ambient light that could reach a surface. Areas in corners and sunken areas will receive shadowing. The numeric value increases the quality and range of effect of the occlusion. Enabling this option will slow performance somewhat. High Quality Light Shading and Material Shaders are required for occlusion to work.

Enables light shadowing from those lights which have their Shadow Type parameter set to a shadowing method. This option decreases performance and increases graphics memory use but greatly improves the quality of the viewport display.

Increasing the shadow quality will improve the shadow’s visualization, especially for area and environment lights, with a corresponding performance decrease.

These values correct for shadow mapping artifacts, which look like moire patterns or 'shadow acne' on surfaces. In general, to fix self-shadowing artifacts 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.

Controls the resolution of the shadow maps, based on the individual light object’s settings, or using a global setting for all lights. Increasing the shadow map size will reduce the jaggedness of shadow edges and improve fine shadow detail. Larger maps may affect performance and will use more graphics memory.

Shows a grid in the orthographic viewport.

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.

The horizontal and vertical distance between grid lines. Click the box between the textboxes to link the values.

Draws every nth grid line thicker. Set this to 0 to not draw thicker lines. Click the box between the textboxes to link the values.

Turning on this option displays a grid for references which divides the uv space with the spacing specified in Reference Grid Spacing.

Allows you to specify the spacing of the reference grid.

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.

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.

Prevents display of the grid outside the image boundaries.

Displays a grid representing the UV boundary around the UV 0-1 tiling of the image.

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.

(File) The path to the image file to use. Click the plus icon to choose the file.

(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.

Controls the fidelity of the background image. Higher values give higher quality background images but use more memory.

Attempts to use hardware texture mapping to speed up and improve the display of textures.

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.

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.

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.

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.

Oversamples the background image to create a smoother, blurry look when zoomed in instead of a blocky look.

Displays textures on geometry. Turning this option off will increase display speed.

Displays all layers of multi-layered textures. Turning this option off will increase display speed when multiple texture layers are present, but only the first layer will be displayed.

When this option is on spotlights render their projected maps in the viewport.

If the Light object has the Projector Map parameter set in its Light/Spot Light Options tab, the map will be used when this option is enabled.

Like Transparency, this is a multi-pass solution with one drawing pass per spotlight in the scene.

This option will not light transparent objects or volumes with the projected texture; they will render as if this option is off.

Increase the quality of displayed textures by producing a mipmap for enhanced filtering. Without mipmapping, textured objects will sparkle when viewed at a smaller scale. Enabling this option will cause textures to use 50% more graphics memory.

Specifies the level of anisotropic texture filtering to use. Higher values increase the quality of textured objects when a surface is nearly parallel to the view direction. This has the effect of sharpening textured objects in this case. The level represents the maximum number of texture samples to filter, and will slightly slow performance as it is increased.

The maximum amount of memory to use for textures, both 2D and 3D. OpenGL always stores textures in main memory and may swap them to and from graphics memory, so this setting can affect the amount of memory available to Houdini. The maximum texture cache size is limited on 32b machines.

Displays the amount of texture cache currently in use. This is for display only and cannot be set. To flush the cache, use Render > Update Textures from the main menu.

When rendering the viewport, if the total size of all textures used is greater than the texture cache size, texture thrashing will result. This causes severe performance degradation as textures are continually reloaded and deleted on every redraw.

If this option is enabled, this situation is detected and on the next redraw, textures' resolutions will be automatically scaled to a size that will fit in the cache. This will cause a momentary performance hiccup instead of a continual performance problem.

If enabled, 2D texture participate in dynamic texture scale reduction. The field next to the option shows the current dynamic scale. If it matches the Scale Textures option, no dynamic scaling has occurred.

3D textures will be dynamically scaled if required during dynamic texture scale reduction.

When enabled, all 2D textures have their size clamped to the specified maximum size. If disabled, textures are clamped to the maximum size permitted by the graphics hardware. Limiting the size can reduce graphics memory used by textures and improve performance, by trading off some detail on larger textures.

Limit the resolution of 3D textures, which are commonly used to represent volumes. If disabled, volumes are clamped at the maximum OpenGL 3D texture size.

Use the 2D HDR Textures and Scale Textures settings for 3D textures, otherwise, they can be specified separately.

Enable High Dynamic Range color and opacity for volumes and other 3D textures. This can improve the quality of volumes at the expense of performance and graphics memory use.

Downscales volumes to a smaller 3D texture, which can be useful for displaying extremely large volume simulations. This scale is applied before the Limit Resolution clamp.

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 .

Displays hulls instead of the actual geometry of objects.

A mask of the visible objects.

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.

Use a simpler shading mode when tracking, zooming, or tumbling to improve interactivity. Choose the shading mode from the pop-up menu.

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.