Scaling Images and PDF Underlays (Reference Method)

Not version-specific

Stabicad

Context In some cases, there is no vector based resource available to be used as Reference for drawing installations. When you insert a PDF or Image (PNG/JPG) as an underlay to trace over, it usually enters the drawing at an incorrect scale. Because you cannot "snap" to pixels in an image, you cannot use a simple calculation. Instead, you must calibrate the image using the Scale Reference method.

Prerequisites

• An image or PDF has been attached to the drawing (IMAGEATTACH or PDFIMPORT).

• The image contains a visual scale bar or a dimension line with a known value (e.g., a wall dimensioned as "5000").

Step 1: Prepare the Reference

1. Zoom in closely on the object in the image you want to use as a reference (e.g., the scale bar or a dimension line).

2. Ensure you can see both the start and end points of that dimension.

Step 2: Execute Scale Reference

1. Select the Image frame or PDF underlay frame.

2. Type SCALE and press Enter.

3. Base Point: Click anywhere near the start of your reference dimension.

4. Activate Reference Mode: Type R and press Enter.

Step 3: Calibrate the Distance

1. Specify Reference Length (The "Wrong" Length):

◦ Click the Start point of the dimension line on the image.

◦ Click the End point of the dimension line on the image.

◦ Tip: Zoom in as close as possible to click accurately.

2. Specify New Length (The "Real" Length):

◦ Type the actual value in millimeters (e.g., if the image text says "5.0m", type 5000).

◦ Press Enter.

Result The entire image/PDF scales up or down proportionately based on that one dimension. The underlay is now approximately 1:1 and ready for tracing.