Problems scaling photo match

I can’t seem to get photo match to scale properly. Importing the photo seems to work OK - I was careful to make sure the camera was level when taking the picture, and I tried with both my iPhone camera and a DSLR. Lining up the vanishing bars goes OK. Then I scale the photo to a known dimension - I tried the vertical, horizontal, and diagonal on the window in the attached file. I used the tape measure CTL-click-click method to scale the photo. House back.skp (2.1 MB)

The problem is when I start drawing the walls. I have the known dimensions of the wall section on the left back of the house. When I draw a wall of those dimensions, it’s way off from the photo. Not by a little, but a lot. It doesn’t match the photo at all.

@Benbo you may find it easier if you setup the matched photo a little differently. You will need to get into the edit mode of the matched photo, and expand the Match Photo tray. Select the options shown below:
Matched Photo Setup
Also, right click on the photo (while in edit mode) and select Rotate 90° right to put the green axis down the side of the house, and the red axis across the back of the house. If you zoom out while in edit match photo, you will see the two vanishing points which you can then grab and move directly. This can be used to adjust for photos that were not perfectly level with the horizon.

Lastly, pull the origin out from the side wall to be even with the two rear walls. Now the trick is to take a measurement of a wall or other dimension (such as total width of the house), draw the corresponding edge or face and adjust the match photo scale by clicking and dragging on any of the three axes (while back in Edit Matched Photo mode).

in edit mode put mouse over blue axis line and drag until your 108’ panel aligns with house.

While you can get accurate at this stage it’s more of a proportional exercise. You can photomatch and draw the whole house and afterwards (once PM is closed) use the tape measure tool to set the scale for the whole model based on a known measurement.

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An issue here is whether the 108" measurement is the height of the actual wall, or of that portion actually visible in the photo (is it partially obscured by the fascia.

Thanks Sasquatch & WhiteRabbit!

Both your tips were a big help. The 108" measurement is the actual wall height. This is the issue I’m having the most trouble getting my head around - how to draw the walls that are partially obscured in the picture. I guess I just need to practice more :slight_smile:

Then use a part that you can see. perhaps the width of the bay window wall where it touches the ground.

@Benbo use the length of the back of the house. You can scale using any of the three axes when in Edit match photo, and you can see the whole back of the house.