Blender and exported .obj files exceeding 2GB even after decimation & limited dissolv

First of all, I am not all that professional working with blender, which made me very proud, that I was able to come up with a complex model which is supposed to be used for a 3D crystal engraving business. Naturally, as I am not a pro, I most likely used a lot of walk arounds and have probably used design methods, any pro would have done simpler, easier and more effective. But for me, optically I am happy with it.

It is a very complex and detailed model of a village in Austria and so far it looks good but it just got to large. The blender file is about 920MB with compressed storage while the exported .obj file is 2.4GB and all that without any During the process I have decimated the model to the limits and also applied various limited dissolve operations as well as I have resized it.

My question would be, what else can I do to get this model smaller in size and ist it normal for complex models like this to blow up to that poinnt? The point cloud conversion software rejects it most likely because of the size.

The attached pic of the model is some 2 weeks old and by now there is more details like trees, boats etc in the model. The pic was taken before I applied the decimate modifier and limited dissolve.

Tnx a lot in advance for your help.

How big will the object be in the crystal and what is the desired distance between the lasered points? From there you could work out the approx max/min size and # of triangles needed to represent the detail you want.

Its possible that much of the detail you have included will never show up.

Well, that may be true for the smaller crystals and to a certain extent even in the larger ones. The point cloud software is pre defined and I cannot alter the distance between the lasered points. I have already tried to decimate more but while some parts of the model can handle it, others don’t at all. The decimate modifier only works on the whole model but not on individual parts/meshes of it. Also tried to create vertex groups. Does not work either. Is it normal, that complex models blow up to this size?

A .blend is a binary scene file, .obj is a ascii model file with accompanying .mtl file that contains material definitions.

Files can be big when you define stuff with real geometry and/or use high resolution/bit depth images. That’s a problem in 3D printing because the print softwares only understand real geometry, and since curves and curved surfaces are defined with straight edges and flat faces, you need lots of it.

Working in a 3D software, or between two or more, there are ways to save resources. Subdivision surfaces, different map types (displacement, normal, bump), instancing, shared data, tesselation.

Yes, with text file formats. Binary formats are very compact.

You might have a look at this not sure what the cost is though, or if you could pay only for the time you need it. Its designed to work with architectural models to provide 3D printable files, but it may also help in this situation.

Looks like there is a free 30 day trial.

Tnx for explaining. I have visited your link. Hell uffa job there, hence far away from where I am or most likely ever will be. But looking at the information it looks like it is not abnormal for a model like this to take that much space. This one is counting about 36.000.000 Verts, 11.500.000 Faces, 22.000.000 Tris. - And that is after decimate and limited resolve. Using up about 7GB of ram working with it.
I guess I have to try to some manual work here to at least eliminate some tris, faces and verts. if I don’t find another way. Tnx for all your info anyway. Learning something new here by the day.

I thought it could reduce complexity by decimating as well. I tried it a very long time ago so I guess my memory was wrong.

It probably is to some extent. I was able to figure out some objects (100s of trees, .obj import) which took a lot of space and I am down to 250MB on the .obj model and 85MB on the blender model. However, I tried various programs and found out that the archtecture is not really solid for printing. I will not be able to eliminate all gaps (and don`t really have to for my purposes), the blender analysis is giving me, but I uploaded it into 123Design in order to find out, how the point cloud would look. Most objects seem to be hollow. No my question: How do I convert the model or individual meshes from hollow to solid in blender?Even after google research, I seem to be unable to find a solution here. Could you give me a hint?

The points will only be on the surfaces of the objects (where the vertices are located). All of the lasered crystals I have seen don’t have points in the interior.