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solidbry

Need help on removing coplanar faces issue

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solidbry

Hi everyone,

 

I have a complex mesh representing underground galeries from a mine. It was made by my client in Promine which is an extension of Autocad for the mining industry.

 

First, I needed to convert this mesh into 3Dface so my software (Geovia Gems from Dassault Systems) can read and import it. This is the easy part and I've already managed to do that in Autocad simply by exploding the mesh which seems to successfully convert said mesh into 3Dface.

 

Where I'm having big problems is that once it's converted into 3Dfaces, I have all the coplanar faces (which seems to be relics from the mesh) of the galeries forming some kind of walls within the tunnels. I can't calculate a volume in my Gems software because those walls are generating a massive amount of self-intersections in the tunnels. The triangulation is pretty screwed-up inside.

 

I thought that maybe there's a way to create some kind of shell only around the outer faces of the galeries while ignoring everything that is inside to get rid of those walls. I've tried the shell modifier but it also create a shell around those pesky coplanar walls inside my tunnels so I end up with the same problem. I've also tried to extrude and vertex weld but no luck there either.

 

In the end, I really need to get rid of those coplanar faces to form an "empty" tunnel. I managed to do it relatively quickly in Sketchup but it seems that this software is doing something to the data and I kind of lose my triangulation and the coordinates of my vertices in the process. Even if I export the result in CAD format, my Gems software says that the file I'm trying to import has no triangulations.

 

I've included a DWG sample (sorry I had to split the file as it was just over the 500kb size limit) of a mining galery corresponding to the original mesh made by my client. I'm using this exact sample to test solutions because the whole complex is pretty huge and takes way to long to test each time. Maybe I'm doing something wrong from the start so I figured that I would provide the original mesh.

 

I've been trying all kinds of procedures and custom scripts in Autocad and tried some stuff in 3DS Max without any good results so far. I really hope that there's a solution besides manually removing each coplanar "wall" since it would take a tremendous amount of time to achieve given the size of the mining complex.

 

 

I'm in no way an Autocad/Max expert but I usually always manage to fix my problems. This issue is one of a kind and I'm unable to fix it :?

 

 

Big thanks!

 

- Bryan

Opening3D_Test.part04.rar

Opening3D_Test.part03.rar

Opening3D_Test.part02.rar

Opening3D_Test.part01.rar

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lrm

Try the following for the co-planar faces:

 

1. Convert the faces to regions.

2. Use the Boolean operation UNION to make it one region.

3. Set mesh option to triangles with MESHOPTIONS

4. Convert the region to a surface with CONVTOSURFACE. Verify that the region has been converted to a surface as there may be two objects, the surface and the region.

5. Convert the surface to a mesh of triangular faces with MESHSMOOTH choose Create mesh when the warning appears.

6. Use EXPLODE to get individual faces.

 

~Lee

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solidbry

Thanks for the inputs Lee, greatly appreciated and easy to follow.

 

Although I think it only partially worked. It seems like the "spatial reference" of my model is gone in the process. See attachment Position.jpg. The blue circle is where the mining complex really is and the red circle is where my test sample is after the whole process. I'm not sure how to fix that :(

 

I'm pretty sure that the co-planar faces are gone but I still have walls from the original faces in my tunnel. See Walls.jpg (from a tilted dropdown view). What I ultimately need to do is to find a way to remove all the darker grey rectangle-like faces in my tunnel so it could be empty. As you can see, I have many of them and this is just from a small sample. That's why I was thinking about going with some kind of outer shell around the tunnel while ignoring everything that is inside.

 

Would it be possible to make some kind of operation(s) to substitute the current model from an outer shell model ? Maybe it would solve my problem.

 

Thanks for your help :)

 

Bryan

Position.jpg

Walls.jpg

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lrm
Although I think it only partially worked. It seems like the "spatial reference" of my model is gone in the process. See attachment Position.jpg. The blue circle is where the mining complex really is and the red circle is where my test sample is after the whole process. I'm not sure how to fix that :(

 

I do not know why the geometry is repositioned. Can you fix this by noting a before and after point to determine how much to move the repositioned geometry?

 

 

I'm pretty sure that the co-planar faces are gone but I still have walls from the original faces in my tunnel. See Walls.jpg (from a tilted dropdown view). What I ultimately need to do is to find a way to remove all the darker grey rectangle-like faces in my tunnel so it could be empty.

 

Can you post a small sample of the file? I would like to see if there is some distinguishing property of the "darker grey walls" from the tunnel side walls.

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solidbry

Yeah I could find the exact coordinates of a specific point in the mining complex and try to move the processed model to that point. There's probably a tool that could assist me in that right ?

 

I've attached a smaller sample which has approximately the same location/extent as Walls.jpg.

 

Many thanks again for your time Lee :)

 

Bryan

test_sample1.dwg

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lrm

I have classified the faces into 2 categories, the barrier walls (B-walls) and side walls (S-walls). The B-walls contain the faces you want to get rid of. I could find no property that I could easily identify with a program. So, I think the approach you may need to take is one of process. I used the following process with some success. Remember that a select widow that goes from left to right selects only those objects that are completely within the window whereas a select window the goes from right to left selects objects within and that cross the window.

 

Note, the file you posted had double faces. It looks like a copy of the model was made directly on top of the original. If this is the case for your master file you may want to look into a routine that deletes duplicate geometry as a start.

 

Here's the process I used.

 

I defined two additional layers Barrier-walls (yellow) and Side-Walls (magenta). I then froze the SIde-Wall layer. Using Free Orbit I rotated the view such that I had a top view but the tunnel I wanted to edit was close to being horizontal or vertical. I then did a select window (left-right) that encompassed a bunch of side walls but never a full barrier wall. I then changed the layer of the selection to the frozen Side-Wall layer. Once I hid the side-wall I could easily change the layer of the Barrier Walls.

 

In this image you can see a select window that selects several hundred faces of the side wall without selecting and barrier walls.

BarrierWalls1.JPG

 

Here's an image that shows a portion of the tunnel with the barrier walls isolated to a separate layer.

BarrierWalls.JPG

 

The process is a bit painstaking but not impossible. Perhaps someone has a better way.

 

Good luck,

Lee

test_sample1-LEE3.dwg

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solidbry

Allright it seems like I have something to work with now :) I'll play around with that process and see if it can be applied to the whole complexe. I could probably split all the level of the mine and treat them separately to ease the processing. While doing some Google crawling on the matter, I stumbled on a 3Ds Max routine that deletes duplicated faces based on their position. I knew it could eventually be handy so I saved it. Let's hope it will do the job.

 

Also, thanks for pointing out the difference between a left-right and right-left selection. I was not aware of that and it's kind of huge when you think about it.

 

I'll let you know if it works. It may take a bit of time though since I'm no expert hehe but I'll keep you posted for sure.

 

Many thanks to you, sir!

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