topic Re: Snapping of 3D solid vertices in AutoCAD Forum

Snapping of 3D solid vertices

naeem_umair27 — Thu, 20 Mar 2025 11:45:20 GMT

I have created a 3D model. It is several solids drawn individual but connected to each other. however, due to extreme tolerance of the CAD software. there are some extremely small distances between the vertices of the solids. Although they appear as if the vertices are snapped to one another. How do I fix this issue in AutoCAD? I want to be able to tell which points are very near to each other and after identifying them, I want to snap them together. I have to import the model into another software which is capable of running a geometry check. When I do, it shows points with relative distances.

Re: Snapping of 3D solid vertices

leeminardi — Thu, 20 Mar 2025 17:30:17 GMT

You cannot easily move a single vertex of some solids. I do not think that you need to for your model. It appears that the individual solids are incorrectly positioned.

I set the units precision to 8 decimal places. I then checked the distance between a set of vertices of two solids. If it wasn't zero I moved it. Starting with the solid object above the lowest solid so that is was precisily positioned. I then moved the solid above it. The result is in the attached file. Please see if this model beter meets your needs.

Let me know if you need more info on the proces I used.

Re: Snapping of 3D solid vertices

j.palmeL29YX — Thu, 20 Mar 2025 18:50:14 GMT

The individual solids already contain minor inaccuracies. Depending on which points on the solids are chosen for placement during assembly, such effects can occur.
As an example, an analysis of the lowest solid.

Re: Snapping of 3D solid vertices

leeminardi — Fri, 21 Mar 2025 01:44:10 GMT

I checked the corners of at least 25 adjacent solids of my final-dam.v01 drawing and the vertices matched to within 8 decimal places.

Distance with osnap end 1 to 2

Re: Snapping of 3D solid vertices

naeem_umair27 — Fri, 21 Mar 2025 06:58:43 GMT

I just want to ask how did you do "I then checked the distance between a set of vertices of two solids...". How do I check the distance between the vertices, thus isolating which points are having issues. I want to be able to check which points exactly do I need to fix. I have to build up on this model adding more solids it will be better if I can check this myself later.
Thank you so much again, you really didn't have to. This means a lot. Wishing you success!

Re: Snapping of 3D solid vertices

naeem_umair27 — Fri, 21 Mar 2025 07:03:20 GMT

This helps a lot. How do I check this myself? Where can I get this window displaying the vertex coordinates?

Re: Snapping of 3D solid vertices

leeminardi — Fri, 21 Mar 2025 15:28:10 GMT

@naeem_umair27

Try the following:

With the units command set the displayed precision to 8 decimal places.
Set object snap to Endpoint only and make it active.
Turn on the properties panel.
Zoom into the a portion of the dam and select a solid. Change its color to red in the properies panel. YOu should see something like this.
Let's say you would like to check the distance from the vertex circled in yellow of the red solid to the "adjacent" vertex of the white solid above it. Give the distance command DI and give a mouse click at 1. Since snap end is active it will snap to the vertex of the red solid. Now click at 2 to get the closest vertex to the white solid.
You can now see that the distance between these two vertices is 0.00000169.
You can now move the red (or whte) solid so that the vertices of the two solids are precisely coincident by using the move command and picking at 1 then 2. Use the DI command again to check that the distance is 0.00000000.

I found that after the move all the vertices of the two solids were exactly aligned. At this point I would make the color of the two aligned solids red and move on to the adjacent solid. Check the distance at vertices that should be coincident and if they are not move the solid as noted above changing the color of the aligned solidss to red to help you keep rack of your process. With a little practice the process is fairly quick. It took me about 10 minutes for the complete model. NOte, care must be used when choosing the two points for the distance comand to make sure which solid's vertex you are snapping to.

Re: Snapping of 3D solid vertices

naeem_umair27 — Thu, 10 Apr 2025 06:17:18 GMT

Thank you so much for this detailed explanation. I will definitely be following this workflow from now on.