# How to extrude surface keeping face angles

I have a simple object with two opposite faces at different angles. I'd like to extrude the connecting face such that the resulting extrusion follows both angles.

I would call this an extrude slide if I were to put a name to it, because it's similar to an edge slide. This scenario happens all the time, but I just can't find a simple way to do it.

What is the easiest way to do this?

My current model:

Normal Extrusion (not ideal):

Ideal Extrusion:

• I don't think that is possible, at all. In your case it seems trivial to guess which edges to move along, but in more complex geometries how would Blender determine what faces to taper along? – Duarte Farrajota Ramos Nov 29 '17 at 17:01
• Blender doesn't need to determine which faces to taper along, it could just taper along all of them. If you select the face and hit {G}{G}, you can slide the entire face backwards along the normals. This would just be the opposite; I don't think it's unreasonable. – SamFall Nov 29 '17 at 17:05
• Actually I found a workaround, will post as answer below. – Duarte Farrajota Ramos Nov 29 '17 at 17:07

As far as I know it can't be done with extrusion directly, but it can be approximated using the Move Along Normals operator.

Select the desired face and press G,G (G key twice) to initiate the Move Along Normals operator.

Move your face "backwards" towards the existing geometry so it slides along existing edges and Blender picks up the correct directions. Once along the desired edges, while moving, press C to unclamp movement.

Once unclamped you can now freely move "forward" towards opposite direction, while still keeping the alignment of the previous geometry.

The downsides of this method are that you won't be able to move in absolute distances in Blender units, only in percentage increments, and there won't be an edge left at the original position, if you did want to keep one there.

• Brilliant! This is exactly what I was looking for. The {C} for clamp I had never heard about anywhere. Thank you – SamFall Nov 29 '17 at 17:31
• Tip: Some operators have additional options while running, check the 3D view header during transform for additional hot keys. This option along with some others is listed there. – Duarte Farrajota Ramos Nov 29 '17 at 17:41
• @DuarteFarrajotaRamos i can't perform an edit that is only 4 characters, so please consider changing the following little thing: "...press C to _un_clamp movement. Once _un_clamped you can now (...)". Clamped is the default state, hitting "C" unclamps the movement – yann Nov 29 '17 at 18:39
• @yann that is right, misread that detail. Its fixed now, thanks for the warning – Duarte Farrajota Ramos Nov 29 '17 at 18:44