Snap on 3d point cloud

[Anonymous]

Hello,

I'm trying to go over a section drawn by a point cloud by hand. To do this, I imported my point cloud in rcp format into Autocad 3d modeling and dissected the cloud using a cutting plane. As long as I work in plan, or I review a horizontal section plane, having the active snaps, every time I move the cursor on the cloud the software automatically recognizes the nodes with the cloud and indicates them using a blue circle with a cross ​​in the middle and this it helps me to go over the cloud. When I try to work on a vertical section but not parallel to the default views of autocad (high, low, front, back), having the 3D object snaps active, the cursor snaps to the cloud but the blue circle does not appear any more whenever I move to the cloud. Initially the cursor worked in the same way both in plan and in section, only after a long time I noticed this annoying variation. I have all the necessary snaps active, I also tried to open a new file and run the section from scratch but the same problem occurs again: cursor that snaps to the point cloud but no blue circle. Instead of the blue circle, some green + appear. I'll send some screenshots as an attachment.

Italian version:

Salve,

sto cercando di ripassare a mano una sezione estratta da una nuvola di punti. Per fare ciò ho importato la mia nuvola di punti in formato rcp in Autocad 3d modeling e ho sezionato la nuvola mediante un piano di taglio. Finchè lavoro in pianta, ovvero ripasso un piano di sezione orizzontale, avendo gli snap attivi, ogni qual volta muovo il cursore sulla nuvola il software riconosce in automatico i nodi con la nuvola e li indica mediante un cerchietto blu con una x al centro e questo mi aiuta nel ripassare la nuvola. Quando provo a lavorare invece su una sezione verticale ma non parallela rispetto alle viste predefinite di autocad (alto, basso, fronte, retro), avendo gli snap ad oggetto 3d attivi, il cursore si aggancia alla nuvola ma non compare più il cerchietto blu ogni qual volta mi sposto sulla nuvola. 
Inizialmente il cursore funzionava allo stesso modo sia in pianta che in sezione, solo in seguito a lavoro ormai avviato ho notato questa variazione piuttosto fastidiosa.
Ho tutti gli snap necessari attivi, ho provato anche ad aprire un nuovo file ed eseguire da capo la sezione ma mi si ripresenta nuovamente lo stesso problema: cursore che si aggancia alla nuvola di punti ma nessun cerchio blu. Al posto del cerchietto blu compaiono alcuni + verdi.

Invio in allegato qualche screenshot qualora il problema non fosse chiaro.

[Alfred.NESWADBA]

Hi,

>> When I try to work on a vertical section but not parallel to

>> the default views of autocad (high, low, front, back)

That sounds like you are using polylines (which are 2d-objects) and have not set the UCS to the coordinate system you need.

So you can use polyline ... but then you need to first use command _UCS to define your user coordinate system (drawing plane)

Or you can use other drawing commands like _LINE or _3DPOLY to not depend on a drawing plane at all.

- alfred -

[Anonymous]

Hi,

I've already put my personal UCS on the face I need, so I'm sure I'm actually in a frontal view but the snap symbol still does not appear. I don't think the problem is due to UCS setting but more on snapping and cursor options.
Anyway, thank you for answering.

Arianna

[Alfred.NESWADBA]

Hi,

which drawing function do you use?

Can you try to use command _LINE ... do you see the object snaps then working?

If not please show the dialog of your activated 3D-ObjectSnaps

- alfred -

[Anonymous]

Hi,

I'm using the 2d polyline because my purse is to obtain a 2d drawing from a 3d point cloud. I've tried to use the 3d poly and line but the snap is still not working properly. I feel the mouse snapping on objects but I do not visualize any snap symbol on the drawing, only the standard autocad white cross.

Arianna

[Alfred.NESWADBA]

Hi,

thank you for your screenshots, please take only the ones you really need, activating all results in troubles quite often.

Again my question: do you get your object snaps shown with command _LINE? We need to know that to continue ... continuing with UCS issues (like dynamic UCS) or with object snaps in general.

- alfred -

[Anonymous]

Hi,

I've just disactivated almost half of the active snap and left only the ones I need, following your advice.
I've also tried to draw using the _LINE command but the snaps are not working. Instead of the snap symbol I see a small text near the cursor saying the type of snap currently detected, for example "Node - Point Cloud".

Arianna

[Alfred.NESWADBA]

Hi,

>> I see a small text near the cursor saying the type of

>> snap currently detected

And when you then click, does the line start at that 3D-position?

- alfred -

[Anonymous]

Hi,

Yes, it does.

Arianna

[Alfred.NESWADBA]

Hi,

>> Yes, it does.

What do you then mean with "snaps are not working" (message 7 in this thread)?

- alfred -

[Anonymous]

Hi,

when I work with snaps on 3d point cloud, I usually see a blue circle with a cross inside, as you can see in the screenshots. It has been a while that i can't see it anymore.

Arianna

[Alfred.NESWADBA]

Hi,

can you please

• create a new dwg-file, attach a point-cloud (a different one if possible)
• turn off object snap (<F3>)
• turn off dynamic ucs (<F6>)
• turn on 3D object snap with just one item "Node of Pointcloud"
• start command _LINE

... do you now get the symbol for 3d object snap?

- alfred -

[Alfred.NESWADBA]

Hi,

btw: do you see a normal object snap symbol for e.g. object snap "_ENDPOINT"?

If not please start command _OPTIONS ==> tab "Drafting" and compare these settings:

One one additional idea ... OSNAPZ is not activated?

- alfred -

[Anonymous]

Hi,

I've followed all the steps but using the same point cloud and it is perfecly working, but still not working on the original file.

[Anonymous]

Hi,

in the original File I see no snap symbol for any 3d snap categories. I only see 2d snap symbols.
I've tried to wrtie OSNAPZ on the keybord but I can't find the command. Can you please show me the path to find it?

Arianna

[Alfred.NESWADBA]

Hi,

currently I have no idea why, but try to turn on layer "Piano sezione orizzontale" in your dwg-file ... does the 3d object snap symbol work well then?

- alfred -

[Anonymous]

Hi,

I've tried but it does not work as well. I think I'll try to reopen the point cloud in a new file and start the project again as it seems to work in this way. Thank you anyway for your help 🙂

Arianna

[Alfred.NESWADBA]

Hi,

turning on all layers does not help too?

- alfred -