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ROWSIM

ROWSIM

Fluid feedback for rowing

Mixed-reality rowing ambient interaction

Begin readingChapter 01

Master's thesis · Interactive edition · 2026

Opening ·Spatial augmented reality

RowSim belongs to spatial augmented reality. Rather than presenting additional numbers or explicit coaching instructions, RowSim projects an abstract, fluid-like visualization onto the floor in the rower's lower periphery, responding in real time to their rhythm and movement.

The intent is to study how such feedback shapes the experience of rowing — engagement, focus, perceived usability.

The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it.

Mark WeiserThe Computer for the 21st Century, 1991
Swift + MetalStudy completed · N=17

Part one · the problem

RowSim

The ergometer answers with numbers.

Concept2 PM5 · performance monitor

  1. Look
  2. Read
  3. Interpret
  4. Return

Each glance is a small departure from the activity[128].
Can feedback accompany it without becoming another task[025]?

[128] Weiser & Brown, 1996 — Designing calm technology[025] Buxton, 1995 — Integrating the periphery

Illustrated from the Metal kernels

Four plates. One fluid.

Trace, disturb, solve, and restore. Each plate pairs a live field with a diagram of the compute step in FluidCompute.metal. Drag on a plate to steer the diagram—not just highlight it.

FIG. 03.1BACKWARD TRACEMove the fieldadvectx* = x − u(x,t)·Δt
FIG. 03.1BACKWARD TRACE
advectMove the fieldOn the grid: the output cell steps backward along u, lands in a 2×2 neighborhood, bilinear-samples, then writes.
FIG. 03.2RBGS PRESSURE
pressureSolveMake it incompressiblePressure is solved on a checkerboard—red cells, then black—so every update reads neighbors that already finished.
FIG. 03.3GAUSSIAN RIPPLE
force + waveInject a strokeLeft: inject and rings. Right: G(x) with ±σ guides; the solid bar is the width 2σ. Drag the right panel to change σ.
FIG. 03.4VORTICITY FIELD
vorticityConfinementKeep the swirlVorticity (ω) is the curl of velocity—the arrows. Confinement is a small force that reinforces that spin so it is not lost to numerical diffusion.

Table of contents

From the floor to the study.

Eight visual chapters sit beside the Thesis. They move from the installation to the study, then to what the interviews named and what the logs cannot say.

Evidence policy

Physical output separates. Engagement does not.

Seventeen adults rowed the same magenta floor under REB 2025-8251. All seven physical-output measures separated elite from casual; none of the six engagement measures did.

Read the study

Governing constraint

∇u0

The pressure projection removes compression from the velocity field. A quiet aside: that one constraint is what makes the motion read as fluid.

Explore all formulas

Source archive

See what the surface is made of.

This site is a reading surface over the same argument as the Thesis: Metal kernels, host code, and the anonymous P1–P17 sessions. Information can occupy the periphery; symbols do not peripheralize well.

Formulas Voyage Thesis & sources