Could not project the selected entities into the current sketch.

famadorian

Here, I'm trying to project the line entity onto the sketch, but it wants me to pick a point, like the end of the line instead. 

I can do that, but it should be able to project this line as a point onto the sketch;)

NeilCooke

Projecting a line normal to the sketch plane is not supported, since the result is just a point that you can reference anyway without projection. What would happen if the line was no longer perpendicular to the sketch plane? The point would turn into a line and your sketch would break.

NeilCooke

Projecting a line normal to the sketch plane is not supported, since the result is just a point that you can reference anyway without projection. What would happen if the line was no longer perpendicular to the sketch plane? The point would turn into a line and your sketch would break.

alnis

Edit: oops, I started writing this before I saw @NeilCooke's post, sorry!

The problem is that you would get undefined behavior if the line gets changed/rotated earlier in the model tree. Should the "use" constraint now make the point coincident with an endpoint of the line? The line's midpoint? Change the sketch geometry to a line and try to reconnect any constraints? I think it's cleanest if Onshape doesn't let you get into this situation by not letting you project geometry that creates degenerate curves/weird setups.

However, it would be nice if there were more of an explanation for why it can't project the line.