Interactivity
Official Tutorials:
Overview
While Syncing Parameters is the easiest way to build control into the Fologram experience, for more immersive experiences or where accessing the Parameters menu inside Fologram is not desired, is article is to start you off with ways to interact with the scene more directly through things like holographic buttons.
Tracking
Use the [Connected Devices] Component to access the connected Hololens devices properties, this gives Grasshopper an awareness of connected devices and how they are interacting with the scene, returning metadata such as device details, or positional data.
These allow you to use this to manipulate data flows and the scene itself.
Just like any other Grasshopper component, the right click context menus and list management options are also available for some components to extend their functionality.
Triggers
Triggers is the concept of how you intend a user to interact to with the scene that can 'trigger' some interactive aspect. There are two main ways provided by the Fologram for Grasshopper library.
Taps
Taps refers to the tapping gesture of the Hololens, allowing you to track if objects have been tapped. This can be tracked through the [Track Taps] component, which gives you the device that initiated the tap, and the item that was tapped. This needs to be enabled through the right-click menu of a Synced Object.
Collision
Collision can be conceptualised as when objects touch 'physically' touch. Such as your hand touching a 'button' geometry.
This can be tracked using any of the components that returns positional data, for example:
[Track Device] gives the transform of the Hololens device itself
[Track Hands] gives the position of the hand model vertices tracked by the camera
Finger Keys
Use finger gesture combinations to trigger behaviours. The provided script is a bare example:
Gaze
Use your gaze (the position of the Hololens device) to trigger. The provided script is a bare example:
Behaviours
With the triggers set up, you can then do basic data manipulation and flows to program a variety of effects.
Showing Rhino Layers
This is a basic setup to demonstrate how to use [Track Taps] to interact with Rhino layers, while you can go through the menus through Fologram to do the same thing, this can be a more intuitive or immersive method.
More generally, this shows how a [Data Recorder] combined with [List Length] and [Modulus] can be used to create a toggling behaviour. This uses HUMAN plugin components to interact with Rhino layers.
Showing Selected Elements [GH]
This is a basic setup to demonstrate how to use [Track Taps]'s returned selected index to show an item corresponding to a button. As long as your list orders are maintained across the two sets (buttons and geometry-to-show), then [List Item] can used to selectively stream from the list.
Note that any geometry that is intended to be tap-able will need to be made so via the [Sync Object]'s Right Click Menu > Clickable.
Incremental Slider
This is a basic setup to demonstrate how [Track Tap] can be used in conjunction with [State Gate] to mimic a slider using a rocker and reset button. [Counter] is used to keep track of the clicks. [Counter] increments every time its Trigger input is updated, we can take advantage of this by using the [State Gate] to toggle these inputs.
Collision Buttons
This is a basic setup to demonstrate the use of [Track Hands] to test for collision with an object to simulate a 'button' interaction by averaging the hand position to use with [Point in Brep].
Air Swipes
This is an example grasshopper script that converts [Track Hands] into data that can then be used in various ways. The script provided is the bare working essentials. Some ways that they may be used might be to inspect an object in 3D or to change a value in an immersive way.
Animation
Animation can be achieved through the [Assign Transform] component. This is used to parametrically update the transform of an already synced object - for example, it can be used to parametrically place an object, such as having it follow the user, or for animation.
Animation can be thought of as providing a series of transforms over a period of time to give the illusion of changes in time. While this could be done by syncing an object over time, using Assign Transform is more efficient as it does not need to send new geometry every transform. This also means that animation is limited to basic transformations and you should be wary about large meshes that may be too taxing on your device.
The general setup is as follows:
Setup how the object should transform, you do not need to transform the object but you can use the Transform output of these components (move, rotate, orient, etc.) to get the transform.
Setup the list of transforms to go through, in this case, Heteroptera's timer-based streaming component is used to scale the transform between 0 and 1 at an increment of 0.001. This could be any list of transform data though.
Use Grasshopper's trigger component as a timer.
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