FAQ: Why don't my background images line up?

[Charlie Thornton]

I imported background images for a multi-floor building into PyroSim. However, when I look at the model in PyroSim, the scale is different (skewed) by a little bit for each floor.  This means that if I try to draw obstructions based on one floor, they won't line up with the next.  How can I fix this?

[Charlie Thornton]

If you are use small distances to set the scale (e.g. a 1 m door) for a background image, it can be difficult to get enough precision to make all of your floors line up.  When using doors to set the scale, you are likely to click a slightly different location on each door or use a slightly different zoom factor.  This error becomes magnified if the door is small relative to the size of the floor.

Try using the longest possible known measurement to specify the scale (best would be the length of the entire structure).  This will give you the least error from choosing the end points of the reference line segment.