Houdini 20.0 Basics

Using the ladder to change values

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When you press and hold MMB over a parameter label or an editable numeric value in Houdini, a value ladder appears that lets you adjust the value by moving the mouse left and right, and adjust the scale of change by moving up and down.

The value ladder lets you adjust numeric values quickly. It can take some practice, but it can be useful for increasing or decreasing a value in small or large increments.

  • Unlike sliders, the ladder has no default range of values: you can use it to make any size change, from very small to very large. It’s also available in places where sliders won’t fit.

  • Once you start adjusting a value with the ladder, you don’t need to pay attention to it anymore. You can concentrate on the effect in the view.

Where you can use the ladder

Parameter editor

  • Press MMB on a parameter name to edit all components of the parameter at once.

  • Press MMB in a text box to edit just that value.

  • When editing an expression, press MMB on a number in the expression to edit it.


Press MMB in any numeric text field.


Press MMB on a handle part to edit its value.


Selected the channels you want to change in the Channel List. In the viewer, hold J and press MMB to edit the selected channels with a ladder.

How to

  1. Move the mouse over a parameter or number field in the interface and press MMB.

    The “ladder” is a vertical stack of numbers representing how much to add/subtract when you move left or right.

  2. While still holding MMB, drag up or down the ladder to choose the magnitude of the changes you want to make.

    For example, to make very small changes, drag down to the 0.01 box. If you are adjusting a rotation, with ranges up to 360 and beyond, you may want to move up to the 10 box.

  3. While still holding MMB, drag left or right to change the value. Each movement of the mouse left or right subtracts or adds the value in the box.

    If you decide you want a different magnitude, drag back to the ladder and move up or down.

    Holding Alt with MMB will multiply rather than add or subtract.


Getting started

Next steps