QCAD.org Forum

before I buy this I would like to know if I can do the following.

I have a jpeg drawing of a building site that has known distances (line lengths) on each side of the polygon. What I would like to do is open QCAD and have this plan showing, then calibrate the scaling so that it matches the known dimensions. For example, one side of the property is a straight line 224 feet long. Can I either warp the polygon uniformly to match a line segment of the same length, or can I somehow use the known lengths of the polygon to calibrate scaling so that all additional site planning work will be to scale. I need to develop a site plan to scale ideally in feet and inches initially (all site measurements delivered are in feet and inches) and then I can convert to metric later on. My hope is that I can set up a baseline from the jpeg plan to allow me draw in as built site features - house, road, etc and have them all to the correct scale within the site boundaries.

Is there a way to do this in QCAD? If not I can't use it. If there is then I can use it. I do not expect to be a regular CAD user so do not really need the full power of a powerful software package.

I appreciate any help with this.

jad1 wrote: ↑

Sun Jun 18, 2023 8:11 pm

Is there a way to do this in QCAD?

Yes and yes - those task are easily achievable in QCAD Pro!

jpg scale to size - yes, QCAD Pro has multiple tools to scale all kind of entities proportional or disproportional.

Converting a drawing from one unit (imperial) to an other unit (Metric) - yes, easy like cake. Covered by tools made for this task ...

jad1 wrote: ↑

Sun Jun 18, 2023 8:11 pm

I do not expect to be a regular CAD user so do not really need the full power of a powerful software package.

Well, don't be confused by the price for QCAD Pro - it is a powerful software package and many professionals all over the world are using it because of that fact!

You can use the tool Modify > Align Reference Points for this:

1. Select the bitmap.
2. Launch this tool.
3. Make sure "Scale" is checked in the options toolbar at the top.

4. Click the first point of the line or feature with the known length (for example 100 units) in the bitmap.
5. Click in the drawing where you want this point from step 4 to go.

6. Click the second point of the line or feature with the known length in the bitmap.
7. Click in the drawing where you want the point from step 6 to go, for example 100 units to the right of the point chosen in step 5.

This rotates and scales the bitmap in such a way that the points chosen in steps 4 and 6 align with the target points chosen in steps 5 and 7.