Hi all,
I’m a mechanical engineer who ended up doing 3D for a living — industrial models, product renders and mechanical explainers. For years, the last step of every technical job was the same detour: export a still, open Photoshop, draw the measurements by hand. Change one bolt spacing and do it again.
So I built the tool I kept wishing existed. DimFlow adds parametric dimension callouts to Blender, built entirely with Geometry Nodes.
First, the obvious question: what about MeasureIt?
Blender ships with MeasureIt and it’s good at what it does — checking distances while you model. But it draws through a viewport GPU overlay, and its render path composites that overlay onto the finished image. The measurements aren’t in the scene.
DimFlow generates real geometry. Each dimension is an object driven by a Geometry Nodes modifier, so it renders in Eevee and Cycles like anything else — your lighting, depth of field, motion blur — and it can be keyframed. That’s the whole reason it exists. If you only need to check a distance while modelling, MeasureIt is free and already installed; use it.
What it does
Four types: Linear, Angular, Radius (with Diameter mode and automatic R / Ø prefix) and Annotation (leader + label).
Placement from Edit Mode. Select points and hit Add — 2 verts gives Linear, 3 gives Angular with the corner on your third pick, 1 gives an Annotation. Works on curve control points too. Orientation is solved automatically so the text is never mirrored or upside down, whatever order you click in, and every dimension lands in its own collection.
Values are live. They read the real geometry, so you don’t need to apply scale. Move a vertex and the number follows. Units in m/cm/mm/in/ft, degrees or radians, decimal control, a measure scale for non-1:1 drawings, and a text override when you’d rather write “Ø 25 H7”.
Reveal animations. Sweep draws the dimension along its own line like a pen stroke; Grow scales it into place. One click keys the whole thing from the current frame with exact frame maths — 40 frames means 40 frames. Animate Disappear keys the exit without touching your reveal keys.
Line styles. Centerline (dashed, with an adjustable dash count and an invert that moves the dashes onto the extension lines) and a Ruler style that stands ISO graduation teeth on the line — every fifth tooth long. On an arc, the teeth fan out radially.
Two scene tools I kept needing: a procedural Blueprint world (graph paper, square cells at any render aspect, no textures or compositing) and a thick wireframe overlay with a Sharp Edges Only mode for dense meshes.
Practical details
- Blender 5.0, 5.1 and 5.2 — tested on each
- Ships as a modern extension (drag the zip onto Blender), not a legacy add-on
- Eevee and Cycles, Windows / macOS / Linux
- Non-destructive: dimensions are separate objects, your mesh is never touched
- Old files upgrade themselves on load — assets carry a version stamp, so your values and keyframes survive updates
- GPL, as add-ons must be
Known limits, so nobody is surprised:
- Face Camera follows the scene’s active camera
- Curves keep no click history, so on a curve an Angular dimension takes the three points in spline order with the middle as the corner
- The wireframe overlay is the expensive part on very dense meshes — that’s what Sharp Edges Only is for
- Not tested below 5.0
It’s a paid add-on on Superhive: DimFlow - Superhive (formerly Blender Market)
Happy to answer anything, and genuinely interested in what’s missing — every feature in it started as a problem on a real job, so if it doesn’t solve yours, I’d like to know what it’s failing at.
Amir