S. J. Zhang


Red for singing plants



What would you do in a world where plants can sing? Red for Singing Plants is a VR Sound experience where plants fly in the sky, trees greet you with sounds when approached. It is a project for my class at ITP called Immersive sound for VR where we explore topics from the base layer of Sound Synthesis to Ambisonic Recording for 360 degree videos, and Virtual Reality.



Unreal Engine

VCV Rack

Logic Pro X




One Week

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To synthesis sound for different plants. I used modular synthesis software VCV Rack with modules from Eurorack to create the sounds from scratch. I had four patches that suit different personalities (plantalities?) that I was happy with. It was really fun turning the knobs and see how the oscilloscope reacts, and then listen to how the graph sounds.


I have attached the raw recorded sounds from the Master Recorder module. As the project advanced, adjustments were made to the sounds later.

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There were effects I had in mind when I was synthesising sounds but was able to achieve in the modular synth. As I was assigning sounds to characters, I processed all the .wav files in Audacity to give them more distinct characters. For example, I used low pass filter for #9 so the sound feels more steady and strong.


I gave keywords to plants based on their physical attributes. Both trees’ sound are non-intrusive since they are static objects on the map, however the flowers will be moving in the air like creatures. With No.10, since the flower’s anther looks like antenas, I gave it an insect like sound. While No.8 looks like a spaceship pod, so I produced a sound that reminiscent of signal stations in retro-futuristic movies.

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After planting hundreds of trees in the map, the first thing came to mind was the sound of wind, and the second was bird’s chirping. Those sound especially bird’s chirping is forest specific so I overrode attenuation in Unreal Engine to customize the spatialization.

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I experimented placing several duplicates of the same background sound in the forest centered in different areas. This way there could be multiple center where birds are gathered and the chirping sound is louder. While the wind sound can overlap and intensify toward the middle of the forest and both sounds would fall off toward the outer edge.

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With all the characters in place the world just need a little lift on richness. I decided to get help from the creators who open source their work to spice up my world. I downloaded several models while these two under really made my scene more lively.


All the trees are static with trigger boxes for sounds right under them. The flowers are animated to repeated motions. The ones moving horizontally pan the audio constantly, while the ones moving vertically also do that if you just tilt your head.