Fix: Incorrect radius values used for Alembic points and USD nurbs

These were reading in "widths" and not adjusting the values when setting
Blender's "radius" properties.

Found while cleaning up the radius API usage as part of another change.

Pull Request: https://projects.blender.org/blender/blender/pulls/134709

source/blender/io/alembic/intern/abc_reader_points.cc

@@ -140,11 +140,11 @@ void AbcPointsReader::read_geometry(bke::GeometrySet &geometry_set,
   const P3fArraySamplePtr &positions = sample.getPositions();
 
   const IFloatGeomParam widths_param = m_schema.getWidthsParam();
-  FloatArraySamplePtr radii;
+  FloatArraySamplePtr widths;
 
   if (widths_param.valid()) {
     IFloatGeomParam::Sample wsample = widths_param.getExpandedValue(sample_sel);
-    radii = wsample.getVals();
+    widths = wsample.getVals();
   }
 
   if (point_cloud->totpoint != positions->size()) {
@@ -163,9 +163,9 @@ void AbcPointsReader::read_geometry(bke::GeometrySet &geometry_set,
       attribute_accessor.lookup_or_add_for_write_span<float>("radius", bke::AttrDomain::Point);
   MutableSpan<float> point_radii = point_radii_writer.span;
 
-  if (radii) {
-    for (size_t i = 0; i < radii->size(); i++) {
-      point_radii[i] = (*radii)[i];
+  if (widths) {
+    for (size_t i = 0; i < widths->size(); i++) {
+      point_radii[i] = (*widths)[i] / 2.0f;
     }
   }
   else {

source/blender/io/usd/intern/usd_reader_nurbs.cc

@@ -150,7 +150,7 @@ void USDNurbsReader::read_curve_sample(Curve *cu, const double motionSampleTime)
 
       float radius = 0.1f;
       if (idx < usdWidths.size()) {
-        radius = usdWidths[idx];
+        radius = usdWidths[idx] / 2.0f;
       }
 
       bp->radius = radius;