Sine Wave: This is typically accomplished using RC (resistor-capacitor) networks and an op-amp. In this circuit, I assume U3 operates as an integrator and U2 operates as an inverting amplifier, and together they form a feedback loop. The output of U3 (sine_wave) is an integration of input voltage. This output feeds back into U2, and this loop will result in a sine waveform due to the integral operation.

Square Wave: This is usually generated with a comparator or flip-flop circuit. In the project, it might be generated from U1. U1 seems to operate as a kind of Schmitt trigger converting the sine wave to a square wave. When the sine wave from U3 exceeds certain thresholds as defined by R2 & R1 resistive divider, the output of U1 will swing from positive to negative rail or vice versa, creating a square waveform.

Triangle Wave: This is often generated with an integrator and comparator in a feedback loop. Here, it could be generated by using the op-amp U2 as an integrator, and U3's output signal. This would generate a triangle waveform that rises and falls linearly with time due to the integrative effect.

LMV321 Op-Amps (U1, U2, U3): These circuits are integral in wave-shaping. Each Op-Amp outputs a specific waveform. U1 is responsible for delivering square waves, U2 outputs triangle waves, and U3 produces sine waves.

Resistors (R1, R2, ..., R12 & RV1): They play vital roles in defining the properties of the operational amplifier circuit, such as gain, frequency, and phase shift characteristics.

Capacitors (C1, C2, ..., C24): Used in conjunction with resistors, capacitors shape the frequency response and stability of the op-amp circuits.

LM27762DSSR (U5): This is the power supply for the op-amps, providing both positive and negative voltages necessary for the operation of the operational amplifier circuits.