snap

[lucas.zaborowski]

I got large scale facade panels rotated and sloping (a bit Gehry-like style), so the slab shape differs from one storey to another. I'm trying to force Revit to snap to objects properly, so when I draw a slab, it snaps to an elevation panel, which has been cut at the proper height. I have set up the cutting plan level to be 0,0 relating to the current storey. Still Revit doesn't snap to the cut profile of the elevation wall/panel, thus the shape of the slab cannot be drawn accurately.
See attached .jpg for a graphical explanation.The desired snap points are market with purple circles on the plan and a section.

Any help much appreciated.

lucas

[Mike Sealander]

I would recommend you turn to reference planes for help. In a lot of situations where two planar elements need to join (or snap) cleanly, you can locate that join edge with a ref plane. Then, use the ref plane to draw your sketch lines. Or, you can use ref planes to create solid voids for carving into your slab, for instance. What helps a lot is to name your ref planes (right click for properties); this way you can find your way through a gaggle of them.

[lucas.zaborowski]

As advised I created a Ref Plane (which actually follows the automatically created floor plane) , still Revit does not snap to the cut profile. It finds the edge (Nearest) but cannot grip a corner (Intersection/Endpoin).
How do I precisely attach such a rotated+sloping wall to the structure at the proper level? Any ideas?
L

[aaronrumple]

You would be best off using a massing model to generate both the walls and the floor....

[lucas.zaborowski]

No difference. Looks like it doesn't matter if it's a mass or an in-place wall, or any other object.
In floor plan view the vertical elements are cut at the level descibed in View Properties -> View Range -> Cut Plane. When set to 0.0 they should be cut at the Floor Level... and the are. Just can't snap to this surface. When trying to move that surface the only snap I can get is 'Nearest' which is not_entirely_accurate.
What do I do wrong? Can't believe it's another bug in Revit.
Anybody came across this issue?
lucas

[aaronrumple]

What I ment was use a massing model to generate the walls and floors. Then there is no need to snap to anything.

[lucas.zaborowski]

So it seems like another bug if you cannot snap points effectively in 2D space. Not mentioning the lack of 3D snap...
I'm so annoyed with Revit being so incomplete and buggy... In acad I'd have drawn all that a week ago. It's even worse, when I was the one recommending and suggesting Revit...

L

[Scott D Davis]

Problem is, you aren't snapping to a point. You are trying to snap to a 'space'. The line on your face is completely variable, depending on exact height. If you make the floors and the panels actually "touch" and intersect, you can use Join Geometry will will cause a line to occur at their intersection. Place a ref plane at this intersection in plan, and use the ref plane as a guide to snap your floor sketch line to.

If you could have done it in AutoCAD 'a week ago', then maybe you should have....but then you'd have a 2D plan/section/elevation that cannot be quantified, scheduled, analyzed, or computed as a BIM model can be. The speed in creation of these things isn't always about how fast one can draw a single plan.

[Mike Sealander]

I have found that I sometimes expect the methodology in Revit to be similar to the methodology in SolidWorks or Viz, for instance. It isn't, and I wish Revit were better at parametric 3d modeling, but I have found that Revit provides a bunch of tools for doing quite a lot: perhaps virtually everything one would want.
The ref plane approach is analogous to drawing in 2d in AutoCAD: you need to create enough references (basically similar in function to extension lines in 2d between an elevation and an xref'd plan) to be able to define the boundaries of the 3d objects you are creating. I don't use massing, but I trust going the mass route would work. Relying on refplanes gives you precision and a level of documentability that will carry on to CDs.
Don't give up! Revit's a good program.

[aaronrumple]

The technique of using join egometry to generate an edge is also very useful in laying out intersections of complex roof. You should find that making the floor bigger than it needs to be and then using join geometry to find the intersection works quite well for what you have drawn.

However there are several other ways to do this maybe even faster and better. I know that if I first generate a mass for a shape like this and then use the sahpe to make the walls and floor - there will be no snapping. And better yet, if I make a design change all I need do is re-shape the mass and then update the floors and walls related to that mass. Very fast.

You could also use an in-place family void to cut the floor at the right spot. This would be more dynamic than drawing the floor correctly. I would just draw the floor oversize and then the void would use a blend shape to follow the back of the wall. This could be used to cut multiple floor levels all at once to the correct plane - even at the correct slice angle as the wall intersects the floor. Again - if the designer were to update - you only need to move the void to update all floors. Also sholud you move a floor up or down - it will automatically be updated.

So - ya - you could find the sanp point. But there are faster ways to let Revit do it all for you without even doing all that manual 2D work.