PlayerMarkerRenderer

Tsvrc.UI.PlayerMarkerRenderer is the pluggable presentation strategy a PlayerPositionOverlay reports positions to. The overlay only ever decides when and where; this class (or a subclass of it) decides what a marker actually looks like and how it's drawn. It's a plain, non-abstract base with empty-bodied virtual methods, deliberately, so a subclass that only overrides one of the two methods still works: the other simply does nothing. A PlayerPositionOverlay with no Renderer assigned is a separate, explicit case: StartOverlay and the tracking hooks all check for Renderer == null themselves and refuse to run rather than relying on this class's own safety for that.

Overriding it

public class MyRenderer : PlayerMarkerRenderer
{
    public override bool UsesHeading => false; // skip the overlay's rotation read if unneeded

    public override void OnMarkerVisible(Vector3 worldPosition, bool isLocalPlayer, float headingDegrees, string playerId)
    {
        // Called once per visible tracked player, every blink-show cycle.
    }

    public override void OnPresent()
    {
        // Called once per blink tick, after this cycle's OnMarkerVisible calls (none, on a hide cycle).
        // Batch-present anything accumulated in OnMarkerVisible here.
    }
}

UsesHeading defaults to true; override it to false if your presentation doesn't care about facing direction, so the overlay skips the extra GetRotation() call for every tracked player, every remote tick. OnMarkerVisible fires per visible player; OnPresent fires once per cycle regardless of how many (or how few) markers were visible that cycle: it's the natural place to do a single batched flush rather than committing per-marker work immediately in OnMarkerVisible. See RasterPlayerMarkerRenderer for a ready-made base that does exactly that.