What Is Rotation Around the Y Axis?
A rotation around the y axis turns a 3D point through a chosen angle while keeping its vertical coordinate unchanged. It is common in analytic geometry, graphics, robotics, and game design. The calculator applies the standard right handed matrix, so positive angles follow the usual mathematical convention.
Why This Calculator Helps
Manual rotation can become confusing when signs, radians, degrees, and pivots are involved. This tool accepts coordinates, angle units, direction, and a custom pivot. It then shows the shifted point, matrix values, rotated coordinates, radius from the y axis, and projected angle in the xz plane. These details make each step easier to check.
Formula Logic
The point is first shifted by subtracting the pivot coordinates. The rotated x value uses cosine with the old x value and sine with the old z value. The rotated z value uses negative sine with x and cosine with z. The y value stays the same during the rotation. Finally, the pivot is added back to the result. This gives coordinates in the original space.
Practical Uses
Students can use the calculator to test homework answers. Designers can rotate model points around a vertical axis. Developers can confirm transformation code before adding it to larger systems. Teachers can build examples that compare clockwise and counterclockwise rotation.
Accuracy Tips
Use enough decimal places for small angles or large coordinates. Choose radians only when your angle is already in radians. Check the direction field before exporting your result. For rotations around the origin, leave the pivot values as zero. For rotations around another vertical line, enter the pivot x and z values. The pivot y value is included for completeness, although y remains unchanged relative to that pivot.
Reading Results
The final coordinates show the new point after rotation. The matrix section shows the exact trigonometric coefficients used. The distance from the y axis should stay constant when the pivot is fixed. The inverse check rotates the answer back by the opposite angle. If it matches the original point, the calculation is consistent.
Export Options
Use the CSV button for spreadsheets. Use the PDF button for reports. Both downloads keep the entered values and computed coordinates together.