Simplify a model

[giacco]

Greetings to all.

I have created an "area 3d" of a city with a GIS software and then import it into 3ds max, the generated model has many faces as seen in the image.

How can I simplify this geometry (many faces are parallel).

[CAMedeck]

If this is an Editable Mesh, or you apply an Edit Mesh modifier, go to Edge sub-object mode and select them all.  Find the Surface Properties rollout in the Modify Tab and you will see Auto Edge.  Set the number to something very low, like 0.1 (this value is an angle) and click the Auto Edge button.  All edges along planar surfaces will be hidden.  You will still have a number of vertices along the remaining edges, but overall things will be greatly simplified.

[giacco]

Hello @CAMedeck, thank you very much for your answer.

I have tried in various ways, but I cannot simplify the model. I attach the 3ds file(rar) . I don't know if I am doing the procedure incorrectly.

Regards.

PD:  My purpose with this procedure is to export the model in DXF format, but I have a limit of 32767 vertices, and as it is a procedure that I must do continuously, I'd like to get a method that doesn't involve splitting the model.

[CAMedeck]

Start by welding the vertices.  You will then need to reset the smoothing groups on the mesh.

[leeminardi]

Can you post a max or zip file?  rar files are a hassle for me.

[leeminardi]

I tried the following on a sample editable mesh and it successfully reduced the face count significantly.

1. Check the face count of one of the buildings (File, Summary Info...)
2. Create a box that totally encompasses one of the buildings (editable mesh) so that the box is larger than the building on all sides including the top and bottom. Note if this works satisfactorily you may be able to create a box the encloses many buildings at a time.  
3. Select the building and then  click ProBoolean (Create, Compuond Objects), choose Intersection then pick the box.
4.  Right-click the resulting object and convert to editable mesh.
5. Check the face count of the resulting object.