diff --git a/src/main/java/com/github/stephengold/joltjni/RVec3.java b/src/main/java/com/github/stephengold/joltjni/RVec3.java
index 8853bcdb..f449dc83 100644
--- a/src/main/java/com/github/stephengold/joltjni/RVec3.java
+++ b/src/main/java/com/github/stephengold/joltjni/RVec3.java
@@ -21,6 +21,7 @@ of this software and associated documentation files (the "Software"), to deal
  */
 package com.github.stephengold.joltjni;
 
+import com.github.stephengold.joltjni.operator.Op;
 import com.github.stephengold.joltjni.readonly.RVec3Arg;
 import com.github.stephengold.joltjni.readonly.Vec3Arg;
 
@@ -137,6 +138,49 @@ public boolean isFinite() {
         }
     }
 
+    /**
+     * Create a unit vector along the 1st (X) principal axis.
+     *
+     * @return a new vector
+     */
+    public static RVec3 sAxisX() {
+        RVec3 result = new RVec3(1., 0., 0.);
+        return result;
+    }
+
+    /**
+     * Create a unit vector along the 2nd (Y) principal axis.
+     *
+     * @return a new vector
+     */
+    public static RVec3 sAxisY() {
+        RVec3 result = new RVec3(0., 1., 0.);
+        return result;
+    }
+
+    /**
+     * Create a unit vector along the 3rd (Z) principal axis.
+     *
+     * @return a new vector
+     */
+    public static RVec3 sAxisZ() {
+        RVec3 result = new RVec3(0., 0., 1.);
+        return result;
+    }
+
+    /**
+     * Separately scale each component.
+     *
+     * @param xScale the scale factor to apply to the X component
+     * @param yScale the scale factor to apply to the Y component
+     * @param zScale the scale factor to apply to the Z component
+     */
+    public void scaleInPlace(double xScale, double yScale, double zScale) {
+        this.xx *= xScale;
+        this.yy *= yScale;
+        this.zz *= zScale;
+    }
+
     /**
      * Set all 3 components to specified values.
      *
@@ -162,6 +206,17 @@ public void set(double[] array) {
         this.zz = array[2];
     }
 
+    /**
+     * Set all 3 components from the argument.
+     *
+     * @param source the vector to copy (not null, unaffected)
+     */
+    public void set(RVec3Arg source) {
+        this.xx = source.xx();
+        this.yy = source.yy();
+        this.zz = source.zz();
+    }
+
     /**
      * Alter the first (X) component.
      *
@@ -206,6 +261,21 @@ public static RVec3 sReplicate(double value) {
         return result;
     }
 
+    /**
+     * Return the component-wise sum of the specified vectors.
+     *
+     * @param vArray an array of input vectors (not null, unaffected)
+     * @return a new vector
+     */
+    public static RVec3 sum(RVec3Arg... vArray) {
+        RVec3 result = new RVec3();
+        for (RVec3Arg arg : vArray) {
+            Op.plusEquals(result, arg);
+        }
+
+        return result;
+    }
+
     /**
      * Create a vector with all components zero.
      *