3D Transformation Matrix Calculator

Apply a 3D affine transformation matrix to a point. This educational calculator shows the formula, result, and step-by-step interpretation.

Computer ScienceLinear AlgebraGraphics Math

Calculator

What this calculator teaches

3D transformation matrices are used in graphics, CAD, robotics, cameras, and simulation.

Use the result as a learning aid. For classwork, still show the formula and intermediate reasoning so the final answer is not just a black-box number.

Understanding a 3D Affine Transformation

A 3D affine transformation combines a linear transformation and a translation. This calculator reads the first three columns as a 3×3 matrix A and the fourth column as a translation vector t, then evaluates p′=Ap+t.

The 3×3 part can represent scaling, rotation, reflection, shear, or combinations of those operations. Translation is not a linear transformation by itself because it does not keep the origin fixed, so it appears as the separate vector t. In homogeneous coordinates, the same operation can be written as one 4×4 matrix acting on [x,y,z,1]ᵀ.

Matrix rowOutput coordinate
Row 1x′=a₁₁x+a₁₂y+a₁₃z+tₓ
Row 2y′=a₂₁x+a₂₂y+a₂₃z+tᵧ
Row 3z′=a₃₁x+a₃₂y+a₃₃z+t_z

Order matters when composing transformations. Rotating and then translating generally produces a different point from translating first and then rotating. A single affine matrix already encodes whichever order was used when the matrix was constructed.

Separate position changes from shape changes. Translation moves every point by the same vector, while the 3×3 matrix determines how differences between points are stretched, rotated, reflected, or sheared. Consequently, subtracting two transformed points removes the translation term: p′₂−p′₁=A(p₂−p₁).

This gives a useful check. If A is a pure rotation matrix, it should preserve distances and angles, so the length of a vector before and after transformation should match apart from rounding. A uniform scale by s multiplies every distance by |s|. A reflection preserves lengths but reverses orientation. These properties help diagnose incorrectly entered matrices.

Formula & Symbols

ConceptFormula or rule
Affine transformp′ = Ap + t

Worked example

Example: The default matrix translates (5,6,7) by (2,3,4).
Example 2: Identity A with t=(0,0,0) leaves p=(2,−1,5) unchanged.
Example 3: A=diag(2,3,4), t=0 transforms (1,2,3) to (2,6,12).
Example 4: Identity A with t=(2,3,4) transforms (5,6,7) to (7,9,11).
Example 5: The z-axis 90° rotation A=[[0,−1,0],[1,0,0],[0,0,1]] maps (1,0,2) to (0,1,2).

Common mistakes

⚠️
Using the wrong input format

Keep lists comma separated, matrices as rows separated by semicolons, and modular inputs as integers.

⚠️
Ignoring assumptions

Some methods require positive probabilities, valid moduli, independent trials, or small educational input sizes.

⚠️
Confusing rows and columns

Each output coordinate is a dot product of one matrix row with the input point, followed by the row’s translation value.

⚠️
Assuming transform order is interchangeable

Matrix multiplication is generally not commutative, so composing rotation, scale, and translation in a different order can change the result.

Homogeneous-coordinate checks should also confirm that translation affects position points as intended while preserving the expected linear part.

FAQ

Can I use decimals?
Most numerical calculators allow decimals, but modular arithmetic and coding-theory tools usually require integers or binary strings.
Is this for homework checking?
Yes. The page is designed to show both the answer and the reasoning pattern.
Why does the result sometimes say approximate?
Some probability, floating-point, and numerical methods naturally produce approximations.
Why is the matrix 3×4 instead of 4×4?
The page stores the 3×3 linear part and 3×1 translation column directly. A homogeneous 4×4 matrix would add the final row [0,0,0,1].
Can this represent a pure rotation?
Yes. Use a rotation matrix for the first three columns and zeros in the translation column.
Can this represent perspective projection?
No. Perspective transformations are projective rather than ordinary affine transformations.
What happens to vectors such as directions?
Pure direction vectors should not receive the translation term; this page is designed to transform points.

Related calculators

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Formula Explorer connections

Interpretation: This relationship connects dimensions, coordinates, angles or trigonometric ratios to a geometric measurement. Assumption: Use a consistent angle mode and length unit, identify the intended shape or coordinate system, and verify that the supplied dimensions form valid geometry.

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