Tracing a point cloud extremely slow

[Anonymous]

To get a job out quickly we have been asked to trace over a laser scanned point cloud. My first thought was to simply use Detail lines using sections through the cloud to get the building outlines, however for some reason this runs extremely slowly, especially when trying to use a spline detail line, the lines are lagging upto 10 seconds behind my mouse clicks in some instances. I'm assuming this is something to do with the point cloud as if i disable it in the view it runs quicker, but i have snap to point clouds/select pinned elements turned off, and the cloud is locked.

My pc is brand new machine with a Ryzen 9 3900x CPU, 32gig of memory, geforce rtx 2060s and im running the point cloud off of a ssd internal drive (i have no issues whatsoever viewing the cloud in a 3D view in revit).

Any thoughts or suggestions?

[martijn_pater]

You could use a section box to work with smaller pieces of the point cloud in 3d views, or reduce points in the point cloud itself.

[Anonymous]

Do you know why this is happening in the first place? Does revit not like a lot of detail lines? 

[martijn_pater]

No, I think it is most likely the point cloud precision/number of points Revit has to show in your views. I think another option could be that you could divide the point cloud into smaller pieces or crop your views to a smaller working area...

[Anonymous]

Have tried reducing the view to only show parts of the cloud at a time and the performance gain is minimal. While the option of reducing the points is an option, im worried about actually being able to accurately pick out the architectural details required on the job in question (a burnt out church). I realise that revit isnt designed for this kind of 2d work but it just seems so odd. 

[martijn_pater]

Maybe you could try adjusting your view depth/clip depth.

[barthbradley]

Your issue is not surprising to me.  That's not typically how you "trace" a Point Cloud in a Revit project -- or do much of anything in a Revit Project.  Generally, the Point Cloud is just a reference for the placement of Levels, Grids, Walls, Floors, Roofs, etc.   Beyond that, we model geometry, typically in Families, and load and place them in our Projects.  Or we create Profiles which are used to create geometry in the Project.  So, I'm not sure I understand what you doing with detail lines, splines, etc.   Could you elaborate please?   

[Anonymous]

In this particular instance, the scanned building was an old church that has suffered fire damage. Nobody in our office has the ability to model something such as this in revit, so we decided to go down to 2D tracing route, not ideal i know and believe me i wish i had the ability to create something like this in 3D, but needs must.

[barthbradley]

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@Anonymous wrote:

Nobody in our office has the ability to model something such as this in revit, so we decided to go down to 2D tracing route, 

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Huh?  So, if that's true; that "nobody has the ability to model something such as this in Revit", then why don't you farm out the work to someone that does have the ability?  

[Anonymous]

As a technician, its not really for me to decide what work we take on and i dont really understand why this has any relevance. Is this the proper way to use revit? no, but i've been given a job and im trying to do it to the best of my ability and at the moment my ability doesnt allow me to model a gothic church.

[barthbradley]

My remarks weren't meant to be snarky. Sounds like they may have been received that way. Sorry.  If the shoe was on the other foot, I'd tell my client/boss/supervisor the exact same thing.  Farming out the work may be more practical and cost efficient.  It's not without merit.  

[Anonymous]

No worries :). My line manager is in agreement with yourself but has been overruled, so we just have to suck it up for now.

[ToanDN]

Turn Off Snap to Point Clouds.

[martijn_pater]

@ToanDNHi Toan, he already did that, "but i have snap to point clouds/select pinned elements turned off"

[Anonymous]

Indeed i have already turned off snap to point clouds. I have discovered if i do the tracing in the sheet view it doesnt lag nearly as much, so it must be something to do with the point cloud interaction. Very messy way of producing a drawing but at least its working for now.