How can i measure projected area of any object in blender ? (Ex. shadow from top view) I'd like to measure the area of the projected front, top or side view of an object.
please give me some suggestion
Thank you.
The easiest way I know :


in orthographic top view, project the UVs from view with U > Project from View :





in the UV/Image editor, export the UV layout as a vector image by going in UVs > Export UV Layout and selecting Scalable Vector Graphic (.svg) :





in Inkscape or Illustrator or any vector program, select everything and disable the stroke to keep only the fill :





still with everything selected, do a union boolean to get a single path :





save the svg file
back in Blender, go in File > Import > Scalable Vector Graphics
with the path imported and selected, do Object > Convert to > Mesh from Curve
do Object > Transform > Origin to Geometry and Alt+G to center the object
still in orthographic top view, scale the object roughly :





in Edit mode, enable snap to vertices, select everything and snap a  vertex to its corresponding vertex on the original mesh, even if the others don't align :





select that vertex and snap the 3D cursor to it with Shift+S > Cursor to selected
select everything and make a vertex on an opposite side of the mesh active with Shift+Right Click twice :





enable Pivot to 3D Cursor and Snap to Active :





scale only horizontally with S+Shift+Z and point your mouse to the vertex corresponding to your active vertex to make it snap :





now that the mesh is perfectly aligned and scaled, go in the User Prefs and enable the MeasureIt add-on :





with everything selected in Edit Mode, go in the Tool Shelf > Display Tab, then click on Area and Show :





the area is displayed as the green circle above shows.