Can’t extrude a sketch that was projected

it seems i can’t extrude a sketch that i projected from another object

Steps to reproduce:

  1. Create new project
  2. Create new sketch - any rectangle will do
  3. Extrude the rectangle
  4. Create new sketch from the top surface of the cube
  5. Project - select top face of cube
  6. Try to extrude from new sketch

What happens if you hide the cube so that only the sketch is visible before trying the sketch extrusion?

You can also just tap top of the cube to get back into Sketch mode, then extrude which will also create a new sketch.

Thanks, but the point was to use projection not to draw a new face

I did try that, see the video. The sketch just doesn’t show solid faces. Even if I draw a new circle or rectangle

hi @alexkrush

I think this is a bug of the HBPM beta version, when the face you project is coplanar with the projection plane. (If the projection sketch is not coplanar with the face, projection works as expected)

After the projection, if you move the projected sketch 1mm above, you can extrude the projected rectangle.
If you move it back 1mm below, the projected rectangle is no longer filled and cannot be extruded, which is not expected.

I believe this is related to the “auto hide already extruded portion of a sketch” behavior, which is still under dev and evolving frequently (the latest beta version of the regular Shapr3D does not behave the same as the current beta HBPM regarding auto hide portions of a sketch).

Yeah, it’s indeed a bug in this specific case, when you are projecting a face to itself. In most cases projections can be extruded, but not here.

Out of curiosity: what are you trying to achieve by using a projection as the source of the extrusion instead of the face itself directly?

I am attempting to make a cover for a box. so i start with a sketch on the ground and extrude a bottom and the walls. and then i want to create a new object above the box for the lid. instinctually, i want to project the bottom so that the lid is based on it and if the size of the bottom changed, the lid will change too

Got it, thanks! We’ll fix the bug as it’s confusing, but in the meanwhile, there’s an alternative that might even be quicker/better: Just simply extrude the top face as it is, setting the extrude type to “New body”. It will follow the shape of the top face, which, in turn, follows the original sketch.

Thanks, but in this particular case (although I simplified my earlier example) I’m looking to make the lid for a hollow box. like this

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Oh, yes. Then as @PEC mentioned above, the best workaround can be adding a construction plane a few millimeters away from the surface, projecting to that, doing the extrusion from that sketch and then moving the body back to the original location via the Align tool. It’s indeed a bit of a hassle :frowning: Fixing it is high on our priority list.

Thanks. Yeah… definitely don’t want to have to do that to make this work. But I am happy to keep reporting features that would bring it up to par with my own usage of Fusion


Hi. I have this same problem and I tend to need this all the time, drawing a sketch on top of another body aligning to the corners or edges of the body. Now the software allows me to draw the sketch and it shows up in the history, but I cannot access it in anyway nor extrude it. I think this is pretty fundamental, any roadmap when this could be fixed?

Hi @MarkusK ! If you cannot interact with that sketch at all, you might be experiencing a different issue. Could you record a short video to confirm the issue?