Point Clouds

[spittle]

We've just had a model created via a point cloud survey.

 

We specified at the start that we want to be supplied with a .dwg that contains 3D solids only.

 

It took a fair bit of effort to get them to do this - I think they overlooked this requirement and perhaps didn't have a full understanding of the difference between solid modelling and surfaces.

 

I'm wondering - regarding the software used for Point cloud modelling, is it easily acheivable to model solids?

 

and would it be fair to say it's just good practice to model concrete and plinths that would be one object in real life, as one solid? This would be what I would do but then I've never used point cloud modelling software.

 

To me it seems like the point cloud has been used more as a guide than used to generate the model automatically.

 

We're going to stick with what I've got but would it have been unreasonable to ask them to produce what I would describe as better quality modelling.

 

Some of the plinths are floating slightly above floor level. They also had issues converting to solids as they didn't reallised surfaces had to be closed to do this - which to me seems pretty terrible for them to be producing meshes with holes in them (some quite obvious).

 

What they've produced looks good but I just want to get a better feel for what we should reasonably expect.

 

If I was to use point cloud modelling software could I expect to model in solids like I would any other model?

 

also it appears like they had no Sweep command to produce handrailings etc. Do any packages have this feature?

[shift1313]

Do you know what CMM they used and what software. A few cad softwares will handle pointclouds(acad not being one of them as far as i know). Ive messed with Point Cloud data and its not pretty. Software used to interpolate this data is necessary. Ive only ever created surfaces from point cloud data so I cant really help you there. Depending on file size and type of scanning(probe or laser) they can increase the sample rate and increase the resolution of their sample to make it easier to create objects.

 

From what ive worked with the software (with your help) will try to model a surface or skin of the part. It is possible to close the surface and create soilds and its easier to do in some softwares than others.

 

is this model an outdoor scene?

[spittle]

It's the internals of a large building with pipes etc. they used a lazer and stitched them together, they use Leica Cyclone I beleive and also had access to Rhino but I think they ditched that as it was only producing surfaces.

 

We wanted 3D solids only, as they're eaier to manipulate and we then imported into solidworks.

 

It looks like they have used the point cloud more as a guide, as all walls and concrete faces are flat. Most of the objects are pretty basic.

 

Just how easy would it be to learn Cyclone? Any rough guideline? Any better ones out there?

 

Bearing in mind I'm happy modelling in AutoCAD, Solidworks and 3DS Max.

[shift1313]

Solidworks will work with pointcloud data. If you have SW Premium look up ScanTo3D. It can import point cloud data and allow you to make solids. I havent done this in SW but came across not long ago. Surface Wizard has an automatic creation function. It will create surfaces but once it has you can close or stich those surfaces. Once they are closed you will be able to create a soild from it.

 

If you dont have SW premium I do not believe you have these functions

[spittle]

Solidworks' point cloud functions are aimed more at small (i.e desktop sized) components. Solidworks will not handle the volume of points that would be used for say a building. You definately need a dedicated point cloud modelling package for this. But I want the end result to be modelled using good practice and be high quality - and ideally 3D Solids only.

[shift1313]

well i have never used cyclone so i really cant offer any input on that. I have used Geomagic and it was fairly simple to use. I used it in conjunction with a FARO arm. I know Geomagic has a 30day trial version.

[spittle]

Was that to create surfaces? Did you use it in any other packages? Was that for the construction/civil industry?

[shift1313]

I work in transportation. One specific example was a point cloud used to re-create a tail light lens(we had to thermoform our own). In that example i used the points as a guide to create a surface of the lens, then used thicken. Ive never used this data to recreate a room or any information like you. I exported my data and played with it both in Autocad and Unigraphics. I also used a lot of the point data in UGS but it wasnt to recreate anything, but more for accurate measurements.