By the end of this guide, you will be able to:

When designing haptics with Haptics Studio, you can control the motor that produces vibration feedback using three fundamental methods: Amplitude Envelope, Frequency Envelope, and Emphasis Points. Each envelope consists of a series of points over time, called breakpoints. You can edit these breakpoints by clicking on the curves to add or remove points, move them in time, and change their values.

The first and most important method for designing haptics is the amplitude envelope. The amplitude envelope controls the strength or intensity of the vibration over time, modulating the amount of force that the motor is creating as it moves. See this simple triangle amplitude envelope with three breakpoints. In this example, we cause the force of the vibration to slowly rise and then descend: It’s like adjusting the volume of a speaker - you can make the vibration louder or softer by changing the amplitude. For example, you might use an amplitude envelope to create a gentle, soothing vibration for a relaxing experience, or a strong, intense vibration for a more energetic effect.

The frequency envelope controls the speed of the vibration over time. It’s like adjusting the pitch of a sound - you can make the vibration faster or slower by changing the frequency. For example, you might use a frequency envelope to create a slow, rumbling vibration for a dramatic effect, or a fast, buzzing vibration for a more playful feel. Similar to the above example, here is how a simple triangle frequency envelope will affect the vibration output:

So far, we’ve been controlling continuous vibration by modulating amplitude and frequency. But what if we want a short and crisp haptic feedback that only lasts tenths of a second, like a sharp button click? That’s where emphasis points come in.

An emphasis point is a short, momentary haptic sensation that can be used to create a sharp, distinct feeling. Like breakpoints on the amplitude envelope, the intensity of an emphasis point can be adjusted to create a softer or sharper click. For example, the buttons on the side of our phones have a short, crisp click when we press them, while older computer keyboards might have softer clicks.

Designing in Haptics Studio is a two step process. First, you convert an existing audio file to haptic envelopes.

Then, you can make manual edits and fine tune the design. The algorithm is run automatically every time you start a new project or add a new audio file to an existing project. It will automatically generate both amplitude and frequency envelopes, as well as emphasis breakpoints. To adjust the output of the algorithm, you can change its parameters by opening the Analysis panel in the right sidebar. Each change of an analysis parameter will automatically trigger the algorithm to run and generate a new output.

We suggest using this step to make the haptic experience as close as possible to your design intent. In some cases, no further manual editing is necessary.

The Gain and Resolution parameters control the amplitude envelope, allowing you to fine-tune the intensity and detail of the haptic output.

The Gain parameter adjusts the overall amplitude of the haptic output. By increasing or decreasing the gain, you can make the haptic feedback more intense or softer. This parameter is useful for adjusting the overall strength of the haptic effect to match your design intent.

The Resolution parameter controls the level of detail in the amplitude envelope. A lower resolution value will result in a smoother envelope with fewer breakpoints, while a higher resolution value will generate a more detailed envelope with more breakpoints. This parameter is useful for adjusting the level of detail in the haptic feedback to match the audio file’s dynamics.

The Sensitivity and Reduction parameters control the automatic creation of emphasis points in the haptic clip’s amplitude envelope.

When converting audio to haptics, the algorithm detects quick changes in energy in the audio signal. These are well suited to becoming emphasis break points. The sensitivity slider allows you to adjust the number of emphasis points that are added to the amplitude envelope. Emphasis points can either replace short rises in the amplitude envelope, such as a click, or they can add texture on top of a longer modulation, such as an engine sputtering while running.

The Envelope Reduction parameter controls the intensity of the underlying amplitude breakpoint that accompanies the emphasis breakpoint. By adjusting this parameter, you can change the perceived intensity of the emphasis point relative to the continuous vibration from the amplitude envelope. A low reduction value will make the emphasis point stand out less, while a high reduction value will make it more prominent.

The final set of parameters in the analysis section control how the frequency content of the audio signal affects the frequency modulation of the frequency envelope.

The Audio Filter Range slider allows you to specify a frequency window from which the analysis algorithm should extract the frequency envelope from the audio. The algorithm will then search for the strongest frequency within that window. This feature is useful when working with audio assets used in a game. It allows you to eliminate high-frequency content from the source audio, that should be heard but not felt, and focus on tracking lower frequencies.

The haptic output range slider controls how the extracted frequency modulation from the audio signal is mapped to the frequency envelope. By adjusting this parameter, you can fine-tune the range of vibrations produced by the haptic output. For example, setting the range from 0-100% will produce wide, sweeping frequency modulation, while clamping the value from 0-20% will produce only lower, smoother vibrations. Similarly, clamping the value from 80-100% will produce only higher, sharper vibrations.

The second step of the editing process is manual breakpoint editing. Haptics Studio allows you to fine-tune and edit the amplitude envelope, emphasis points, and frequency envelope. Manual editing is typically done to make minor adjustments before finalizing the haptic design. This feature gives you precise control over the haptic output, allowing you to make subtle changes to the amplitude, emphasis, and frequency to achieve the desired feel.

To add a breakpoint in Haptics Studio, move your cursor between two existing breakpoints. A plus sign will appear indicating that you can add a new breakpoint at that position. Simply click on the plus sign, and a new breakpoint will be added.

To remove one or more breakpoints, first select the breakpoint(s) you wish to remove. Once selected, press the Delete button on your keyboard. This action will remove the selected breakpoints.

To modify a breakpoint, hover over it and click while holding down the mouse button. Once selected, the breakpoint can be dragged to a new time position or value. If you would like to keep the current time position of the breakpoint but modify its value, you can press and hold the Shift keyboard button while dragging.

To set a breakpoint at a specific time or value, you can manually enter numeric values in the Edit Panel in the right sidebar.

To select multiple breakpoints, left-click and drag over the breakpoints you want to select. After releasing the mouse button, you can shift the breakpoints’ position in time, or scale their values by dragging the handles on the top or bottom of the dotted bounding box.

You can cut or copy one or more breakpoints using keyboard shortcuts or the Edit menu. After pasting, the breakpoint(s) will appear in the center of the edit view. You can then drag them left or right to reposition them in time. Additionally, you can also paste your selection in place.

To create an emphasis breakpoint, select a breakpoint on the amplitude envelope and press CMD (CTRL) + B. The breakpoint will be converted to an emphasis point, which will be marked in green.

To remove an emphasis breakpoint, select it and press CMD (CTRL) + B. It will be converted back to a single amplitude breakpoint.

An emphasis point will automatically create an underlying point for the continuous vibration and reduce that point’s intensity to allow the emphasis point to stand out. You can adjust the intensity of both the emphasis breakpoint and underlying amplitude breakpoint by selecting and dragging.

To change the sharpness of an emphasis point, select the point and a pop-up will appear at the top of the editor. Selecting the rounded icon on the left of the popup will create a soft emphasis point, while selecting the sharp icon on the right will create a sharp emphasis point.

Read the Haptic Design Guidelines or check out our Advanced Editing Tips tutorial to learn more about best practices when designing haptics for your apps.