SPZ writing, exporting, & viewer. Creates a new npm run to-spz which runs scripts/to-spz.js to convert any Gsplat input file to compress .spz. Also includes a configurable viewer examples/viewer that can load splats via drag-n-drop, from url query param, the URL text list, can edit sets of SplatMesh, and export composite .SPZ with some filters. Refactored some loading code from worker.ts to loader files so they can be called from Nodejs. Created api transcodeSpz with options to combine multiple source Gsplat files into one without losing coding quality along the way.

src/splatConstructors.ts

@@ -214,6 +214,8 @@ export function textSplats({
   textAlign,
   // line spacing multiplier, lines delimited by "\n" (default: 1.0)
   lineHeight,
+  // Coordinate scale in object-space (default: 1.0)
+  objectScale,
 }: {
   text: string;
   font?: string;
@@ -223,6 +225,7 @@ export function textSplats({
   dotRadius?: number;
   textAlign?: "left" | "center" | "right" | "start" | "end";
   lineHeight?: number;
+  objectScale?: number;
 }) {
   font = font ?? "Arial";
   fontSize = fontSize ?? 32;
@@ -230,6 +233,7 @@ export function textSplats({
   dotRadius = dotRadius ?? 0.8;
   textAlign = textAlign ?? "start";
   lineHeight = lineHeight ?? 1;
+  objectScale = objectScale ?? 1;
   const lines = text.split("\n");
 
   const canvas = document.createElement("canvas");
@@ -276,7 +280,7 @@ export function textSplats({
   const rgba = new Uint8Array(imageData.data.buffer);
   const splats = new PackedSplats();
   const center = new THREE.Vector3();
-  const scales = new THREE.Vector3().setScalar(dotRadius);
+  const scales = new THREE.Vector3().setScalar(dotRadius * objectScale);
   const quaternion = new THREE.Quaternion(0, 0, 0, 1);
   rgb = rgb ?? new THREE.Color(1, 1, 1);
 
@@ -287,6 +291,7 @@ export function textSplats({
       if (a > 0) {
         const opacity = a / 255;
         center.set(x - 0.5 * (width - 1), 0.5 * (height - 1) - y, 0);
+        center.multiplyScalar(objectScale);
         splats.pushSplat(center, scales, quaternion, opacity, rgb);
       }
       offset += 4;