BricsCAD Command: Pointclouds, Optimize, Fit Planar

RogerioA

Hello everybody,
I watched the presentation of BricsCAD BIM V22
https://www.youtube.com/watch?v=BiWXMrJWtI8
At approximately minute 26:00, the workflow shows the amazing "fit planar", "optimize" and "invert spaces" features.
My question is about the "optimize" step and the logic of changing the walls and slabs to be coplanar and perpendicular. If the objective is to make an as built model for eventual reforms, what are the advantages and disadvantages of this step?
Can anyone give feedback on this subject based on your own experiences?

Piet

Hi,
We added the optimization part for 2 reasons:
* a wall that spans multiple rooms can have slight deviations (a few mm) this would result in separated walls
* running the invertspaces on non optimized geometry often does not result in a good model

ScottS

This is a good question, @RogerioA, with both philosophical and technical aspects. Could there be a way to preserve the "true" geometry of a surface but work with its idealized geometry as needed to optimize certain modeling operations, as a further degree of "level of detail" that could be controlled?

Tom Foster

Woo - sounds sophisticated - good. Easy to be led astray by idealised (simplicised = naively over-simplified) geometry, which as we know is never but never really like that. Often we need the true , not even planar geometry, to derive dims of abutting fabrications, custom made windows etc, if tidy fit is important or even to make junctions waterproof as designed/detailed. We draw the measured survey as simplicised and then proceed to think it's really like that, months down the line.

ScottS

Tom Foster said:

Woo - sounds sophisticated - good. Easy to be led astray by idealised (simplicised = naively over-simplified) geometry, which as we know is never but never really like that. Often we need the true , not even planar geometry, to derive dims of abutting fabrications, custom made windows etc, if tidy fit is important or even to make junctions waterproof as designed/detailed. We draw the measured survey as simplicised and then proceed to think it's really like that, months down the line.

Right, exactly. How great would it be if the BIM could do the remembering for us? Let us work with your simplicised model or maximum tolerances during early schematic design or speedy pricing takeoffs, and then regenerate the more accurate surface when it comes time to display an enlarged detail section, say, to remind us of the messy reality when it becomes relevant.

Michael Mayer

I wanted to chime in much earlier into this very interesting Thread.
But realized it will get too complicated.

For me personally,
I am so happy that Bricscad (as a first App that I use) offers such rare but great Tools like OPTIMIZE !
Or even FITPLANAR, have not seen this before. Still manual human work/control needed though.

I currently try to model a house planned in the late 60ies, build in early 70ies.
It has quite some architectural qualities, at least for current standards at that time.
The only planes are from preliminary designs at structural level.
I try to reconstruct the model from finishing dimensions, from room to room.
I did a site measuring and Archicad BIM Model already in 2010, but how far you can
be off when remeasuring today.
(Wondering that a 2m+ bed would finally not fit between Wall and Door in real dimensions)

I am interested in getting the essence by e.g logical brick grid dimensions, where applicable,
despite the build tolerances, to finally get a logical model to estimate where insulation was
used or not, floating screed can have been used as advertised or not and such things.
With the real room dimensions in the back of my mind.
And it looks like, by iterating Dimensions, I come closer and closer to a Model that fits more
and more to all local detail measurements.
OK, it is still hard to really estimate (differing) structural Slab sizes and Floor package thickness,
which Walls are really Brick or Concrete though, or at which level they will switch to Brick.

Of course I can't order a laser measurement for that, which would make it much easier.
(Maybe I should buy an iPhone 13 Pro with Lidar to bring more things together)

And if there would be more differences in being rectilinear and straight walls like in a pre WWII
building, which is not much the case here, I would tend to add totally straight furniture or kitchen
elements, with a clear distance in front of a "round" Wall as I did in my pre WWII apartment.
This is my philosophy, style or approach.
So I am really very happy with Bricscad's Direct Modeling, Optimize and Point Cloud capabilities !

But,
if you really want to exactly document just all imperfections of the existing Building ...
Bricscad should offer any option for FITPLANAR, to choose a MESH-that mess-exactly,
that-looks-somehow-planar-/-in-relation-to-all-touching-Floor/Wall/Ceiling-Surfaces-
that should be exactly being meshed from all Point Cloud measurements too, ....
so that the Carpenter can finally fill his CNC with all real world dimensions to
create a custom fitting Furniture that will finally fit by nanometers.

Alij

Is the fit planer meant to take an average of the spray noise of the point cloud?

RogerioA

Hi, again!
I have a point cloud file produced by 3D Mobile Laser Scanner, so I do not have "bubbles" to use the Bricscad's fit planar as showed in the video.



So, as the image shows, I tryied to use fit planar in low resolution. The results are some planes that I have to edit. But I do not have this knowledge.

Does somebody have a suggestion of workflow to make a 3D model with this point cloud (without bubbles) in bricscad?

Michael Mayer

I am no Point Cloud expert.
I always thought the Bubbles are just a nice way to navigate you model
and get to the points of best point density view at the laser position..
(Usually these Bubble Views look like a real Photo or Pano)

I do not really think these Bubbles are mandatory to create Planes
and Spaces from Point Clouds.

AFAIR there were a few newer very enlightening Videos about Point Cloud
usage on Bricscad's YouTube channel.

This looks new, Bricscad for Surveying Playlist :


Looks like old school Fit Planar is more and more replaced by Tools like Quickwall
that adapts to the underlaying point cloud.

This is just a Preview, but AFAIk there was somewhere a more in depth Webinar
https://www.youtube.com/watch?v=fJV0OtmsH_Q&list=PLONdQc9bizscmuIgUggFg-OTj8TH8pE1R&index=4


https://www.youtube.com/results?search_query=Bricscad+point+cloud

Tom Foster

Michael Mayer said:

I am no Point Cloud expert

Me neither - I wish I was but (unlike MM I guess) I'm a slow digital learner and pressure of work limits acquisition of such skills which would help fundamentally. If only I worked in an office where an expert could show me in 5mins!

However, AFAIK bubbles only exist where the survey was done from a few fixed stations - a 'structured' PC - rather than from a moving drone or similar - 'unstructured'.

Michael Mayer

Tom Foster said:

However, AFAIK bubbles only exist where the survey was done from a few fixed stations - a 'structured' PC - rather than from a moving drone or similar - 'unstructured'.

Yes, Bubbles are delivered by fixed stations only.
I just do not think they are mandatory.
Maybe there is even a way to manually create bubble definitions for any point cloud (?)
They are helpful to jump in 3D View, rotate view around POV and offer the best
point view quality.


I think the way to create the model from a point cloud without Bubbles
is exactly the same as shown in the Video linked in the first posting.
From about minute 17 - 28.
(Fit Planar, Stitch, Spaces, Model from Spaces, ...)

Just that you have to navigate view in your 3D manually.

Tom Foster

Thanks MM, that is clarifying - for when the time is right to grasp all this.