UrbanAbode

I can not find the 3D background setting in X10! I opened a plan from X9 in X10 and it preserved my background setting where I had removed the image and just replaced with a dark grey color. The problem is that I can't find where to adjust the color now. The issue is with the 'line drawing' view - the line drawing view is showing the dark grey outside color as the background. Where can I change background and adjust color or change background images in X10. Please help!