BlitzDim

Turn a single cut line into a complete chain of aligned dimensions. Select your layers, draw the line, drag to place — done.

🧱Select layers
✂️Draw the line
⊙Auto-detect
📏Place chain

Core features

Dimensioning at the speed of thought

Automated chain dimensioning with layer filtering, threshold merging, and a live preview before you commit.

📏

Chain in one sweep

Draw a single cut line through your section or floor plan. BlitzDim finds every intersection with your selected layers and places a complete chain of aligned dimensions — all at once.

Key: One line in, full dimension chain out.
🎯

Layer-precise scanning

Pick exactly which layers to scan. A searchable checklist lets you include walls and exclude furniture, annotations, or anything that would create noise. Settings persist inside the DWG.

Key: Filter by layer, scan blocks recursively.
👁️

Live jig preview

After scanning, a real-time preview of every dimension follows your cursor. Drag to set the offset distance, click to commit. Nothing is placed until you confirm.

Key: See before you place — cancel anytime.

Control center

The Settings Palette

A dockable panel with threshold control, block scanning toggle, and a searchable layer list. Settings persist inside the DWG.

📏 BlitzDim

☰
Settings
Threshold2.0
Scan Blocks
Layers3 selected

CompanionBits

The BlitzDim palette — select layers, set threshold, click Dim.

The palette has three sections: the Settings area with threshold and scan blocks toggle, the Layers checklist with search filter and selection count, and the 📐 Dim button that activates once at least one layer is checked.

Everything is saved inside the DWG as an Xrecord. Layer selections use handles instead of names — if you rename a layer, BlitzDim still recognizes it on the next session.

Step by step

Workflows

Click the task that matches what you need to do.

The BlitzDim palette is your control center. It stores your layer selection, threshold, and block scanning preference — all persisted inside the DWG file so they survive save/close cycles.

  1. Type BLITZDIM in the command line, or click the BlitzDim button in the CompanionBits ribbon.
  2. The palette opens and docks to the side of your drawing area.
  3. If this is the first time, the layer list loads all layers from the current drawing with none selected.
  4. If settings were saved previously (in this DWG), they are restored automatically — including layer selections, threshold, and the scan blocks toggle.
Persistence: BlitzDim stores settings as an Xrecord in the Named Objects Dictionary. Layer handles are stored instead of names, so renamed layers are still recognized.

Layer selection is the most important step. It determines which geometry BlitzDim scans for intersections. Choose your structural layers (walls, columns) and leave out furniture, annotations, and hatches.

  1. In the Layers section, browse or search for layers by name.
  2. Check the layers you want to include. The selection count updates in real time.
  3. Use the "Show only selected" filter to review your choices in drawings with many layers.
  4. Your selection is saved automatically when you run a dimension command or close the palette.
Tip: Start with just your wall layers. You can always add more layers and run BlitzDim again — each run creates an independent chain.

The threshold controls how close two intersection points can be before BlitzDim merges them into one. This is essential for double-line walls: without merging, you'd get two dimension points per wall instead of one.

  1. In the Settings section, adjust the Threshold value.
  2. The value is in drawing units. For mm-based drawings, try 2.0. For cm-based drawings, try 4.0.
  3. Set to 0 to disable merging entirely — every intersection gets its own dimension point.
How merging works: Points are sorted by distance from the start point. BlitzDim walks through the sorted list: if the next point is within the threshold of the current anchor, it replaces the anchor. If it's beyond the threshold, a new segment starts. This collapses double-line walls into single dimension points while preserving real gaps.

This is the core workflow: draw a cut line, let BlitzDim find intersections, then drag to place the complete dimension chain.

  1. Click the 📐 Dim button in the palette — or type BLITZDIMRUN.
  2. Click the start point of your cut line.
  3. Click the end point. A rubber-band line shows the direction.
  4. BlitzDim scans all entities on your selected layers, finds intersections with the cut line, and reports how many points were found.
  5. A live preview of the complete dimension chain appears. Move the cursor to set the offset distance from the cut line.
  6. Click to place all dimensions at once. They are added as standard AlignedDimension entities.
Cancel anytime: Press Escape during any step — nothing is committed until you click to confirm the dimension line position.

When "Scan Blocks" is enabled, BlitzDim looks inside block references to find curves on your selected layers. This is critical for drawings where walls, windows, or structural elements are blocks.

  1. Enable Scan Blocks in the palette settings (on by default).
  2. BlitzDim recursively enters every block reference in model space, applying the block's transform matrix to get correct world coordinates.
  3. Nested blocks are scanned too — blocks inside blocks are resolved with accumulated transforms.
  4. Layer filtering still applies: only curves on your selected layers are included, even inside blocks.
Performance note: In very large drawings with thousands of nested blocks, scanning can take a moment. If you know your wall geometry is not inside blocks, disable this option for faster results.

BlitzDim uses whatever dimension style is current in AutoCAD when you place the chain. It also respects the DIMLAYER system variable, so dimensions land on the correct layer automatically.

  1. Set your preferred dimension style before running BlitzDim — use the DIMSTYLE command or the Properties panel.
  2. If your dimension style is annotative, BlitzDim creates annotative dimensions that scale correctly in paper space viewports.
  3. Set DIMLAYER to a layer name (e.g., "DIM_Maten") and BlitzDim will place all dimensions on that layer, regardless of CLAYER.
  4. If DIMLAYER is empty, dimensions are placed on the current layer.
SwiftSwitch combo: Use SwiftSwitch to set your dimension style, target layer, and DIMLINEAR command in one click — then switch to BlitzDim for the actual placement.

Under the hood

The Intersection Scanner

How BlitzDim finds, filters, and merges intersection points along your cut line.

FeatureDetail
Entity typesLine, Polyline, Arc, Circle, Ellipse, Spline
Block scanningRecursive — nested blocks resolved with accumulated transforms
Z-flatteningAll geometry projected to Z = 0 before intersection calculation
Duplicate filteringCoincident points removed before threshold merging
Threshold mergingCluster-based — walks sorted list, merges within radius
Sort orderPoints sorted by distance from the cut line start point
Intersection methodCurve-curve intersection via AutoCAD geometry API
OutputAlignedDimension entities using the current dimension style

The scanner processes all entities on your selected layers. For each entity, it calculates curve-curve intersections with the cut line. Points are collected, flattened to 2D, de-duplicated, merged by the threshold value, and sorted by distance from the start point. The result is a clean list of dimension points ready for the chain.

Reference

Commands

AutoCAD commands to control BlitzDim from the command line.

BLITZDIM

Open the BlitzDim settings palette. Layer selections and threshold are loaded from the DWG.

BLITZDIMRUN

Run the chain dimensioning workflow: pick cut line → scan → jig preview → place. Also triggered by the 📐 Dim button.

Ready to get started?

Try BlitzDim free for 14 days — no credit card required.

Schedule a demo