Houdini 19.5 Reference Windows

Display options (image view)

On this page

In a compositing viewer pane, open the right side toolbar and click Display Options or press D to open the Display Options window.

In MPlay, choose Settings ▸ Display Options.

Display tab

Auto mipmap images

Generates mipmaps on demand when the image is zoomed more than 3x. This may cause a slight delay during scaling as Houdini generates the mipmap.

Pop window when rendering images

Brings MPlay to the front when a render begins.

Render over previous image

When this option is turned on, rendering to MPlay will copy the previous image onto the new image as a background so that slight changes can be compared as the new image renders.

Fast Pixel Aspect Ratio Display

Images with pixel aspects not equal to one are stretched (>1) or squashed (<1) to approximate the image on hardware devices with non-square pixels. If this option is turned on, a simple hardware scale is used. If off, a slower but more accurate software filter is applied.

Show Borders of Currently Working Tiles

Shows the currently rendering/cooking tile(s) by drawing a corner box at its location.

Viewport tab

Multi node display

Split views/single view.

Layout horizontally first, then vertically

When on, adds images to viewports horizontally first, when the viewport has multiple rows/columns. When off, adds images vertically first.

Show all viewports always

Keeps all viewports visible, even if whole rows or columns of viewports are empty. When off, the view dynamically adapts the viewport layout to the number of images available.

Default viewport layout

Specifies the initial layout of viewports, from 1×1 to 4×4.

Display viewport information

Controls the amount of information shown in viewports. Minimal shows only the name, Verbose shows all information available.

Image guide

Stereo Display Mode

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


You can use passive polarization glasses to view the images in horizontal interlace mode.

Background tab

The viewer always stretches the background image to fit the size of the currently displayed image. If the aspect ratio of the background image and the current image do not match, you will get distortion of the background image.


Choose the file to use as the background image.

Use Res

Manually specify a resolution to use for the background image instead of using the natural size of the image.

Foreground images are pre-multiplied

Most rendered images are pre-multiplied, which means that the color has already been multiplied by the alpha plane.

However, if you place an arbitrary alpha plane without running it through a Premultiply COP, the resulting image is not pre-multiplied, and you must turn off this option or your transparency will be wrong.

For example: place a File COP, append a Shape COP and have it replace the Alpha plane with a star shape - then enable transparency. You’ll need to turn off Foreground Images are Premultiplied to see the proper image.

Background color

Background color of the image viewer, default is black. Click the color swatch to display a color picker.

Correction tab

Display LUT

Choose a LUT file to apply to the images.

Inspect LUT

When inspecting, run raw values of the image backwards through the LUT file to produce the original values (Cineon values).

Default display gamma

The default gamma applied to all images. You can interactively change gamma using the color correction controls.

Gamma correct planes

The names of planes the viewer should gamma correct. Normally, this is just the color plane (C).

Gamma correct background color and image

Whether to apply the gamma correction to the viewport background color and the background image.

Apply Brightness/Contrast before LUT

If on, the brightness/contrast (and black/white) controls in the correction toolbar are applied to the color before the LUT is applied. Otherwise, they are applied afterward. Gamma is always applied last.

Handles tab

Render with smooth lines

Anti-aliases handle and guide lines.

Render with alpha blending

Makes handle and guide lines slightly transparent.

Handle color

The default color for handles and guide lines. Click the color swatch to show a color picker.

Handle pick size

The size of the handle’s clickable area, in pixels. Larger values make the handles easier to grab.

Handles/output follow

Current Node(s), Current/Display, Current Node.

Memory tab

Limit viewer memory usage

Limits the amount of cached image data to the Image cache size.

Memory Usage

Dictates how much memory MPlay will use to cache images for playback in Mb.

Clear images from memory

Flushes the image cache, freeing all memory except the memory used by the currently displayed image(s).