TouchDesigner Audio-Driven Graphics Experiment: From Shape Transformations to Microphone Input Control
Recently, I have been experimenting with TouchDesigner to explore dynamic shape transformations and audio-driven visual effects. Initially, I focused on modifying basic geometric forms using Noise, Output-Derivative (Slope), Threshold, Level (Gamma Adjustment), and Bloom Effects. Later, I integrated microphone input to control shape size and color, using Transform SOP for scaling and translation, with two Null CHOPs managing position and color separately.
1. Initial Shape Transformations and Visual Experiments
① Noise + Output-Derivative (Slope) I started by applying Noise CHOP to introduce organic movement into the shape.To enhance the natural transitions, I used Output-Derivative (Slope CHOP) to smooth out the rate of change, preventing sudden spikes in movement.
② Threshold + Level (Gamma Adjustment) Threshold CHOP was used to create high-contrast effects, transforming smooth gradients into distinct binary patterns. Level CHOP (Gamma Adjustment) helped fine-tune the brightness curve, making the visuals either softer or more dramatic.
③ Bloom Effect Finally, I applied a Bloom effect, enhancing the highlights and adding a glowing aura to the shape, making it more visually engaging.
2. Using Transform SOP for Background, Scaling, and Positioning
To better organize the visuals, I utilized Transform SOP to: Add a background (either static or gradient-based). Control scaling dynamically. Apply translation effects to move the shape across the screen.Link transformations to audio input, so that sound influences both size and position. Additionally, I created two Null CHOPs: One for Position (to control movement based on audio input). One for Color (to change the color dynamically according to the audio intensity).
3. Integrating Microphone Input with Audio Device In CHOP
After experimenting with basic shape transformations, I moved on to controlling these parameters with real-time audio input.
① Capturing Microphone Input Using Audio Device In CHOP, I connected my microphone to feed real-time audio data into TouchDesigner. The raw audio data fluctuates too quickly, so direct mapping would result in erratic visual behavior. To ensure a smooth transformation, I applied additional processing.
② Smoothing Audio Input: Filter CHOP + Lag CHOP .Filter CHOP: Set Filter Width = 2.0 to smooth out the fluctuations, reducing rapid jumps. Lag CHOP: Applied a gradual transition effect: Lag Up = 1.2 (slower increase when the volume rises)Lag Down = 3.0 (even slower decrease when the volume drops)
③ Mapping Audio Data to Shape Scale with Math CHOP Mapped the volume range (0.01 ~ 0.3) to shape scale (0.5 ~ 2.0).This ensures that louder sounds gradually enlarge the shape, while softer sounds slowly shrink it, avoiding sudden jumps.
4. Connecting Audio Data to Transform SOP Mapped the output of Math CHOP to Transform SOP’s Uniform Scale, enabling shape size changes based on audio intensity. Connected Null CHOP (Position) to Translate parameters so that the shape moves dynamically with the sound. Linked Null CHOP (Color) to the color channels, allowing the shape’s color to shift depending on volume levels.
