Any tips on simplifying a complex model???

I have a complex 3d engineering model and want to "print" something looking like it, but it does not have to be exact.

I know many details are too thin to print, and think the simplest would be if I could just make everything have a minimum dimension or stretch everything in 3 dimensions very slightly. I know it would end up less exact, but it should be good enough. Does anyone have any tips for a new beginner on how to do this in say MeshLab???

What file format? If your just looking to scale it up, there are many programs you could use. If it has thicker area's I'd use blender. Then you can scale it up so the thinner parts are thick enough, and you can hollow out the thicker areas.

Thanks. The format is obj, but converted from autodesk.

It's a large and complex model, and scaling it up will only make the whole thing larger (I think). It also wont lend it's self to hollowing out as most details will remain very thin. eg many parts may just be flat or very nearly flat and have no mass. That's why I though of stretching it very slightly in each dimension, so every detail would gain enough mass for printing. I'm just not sure how to do this! Any more ideas?

Well if you stretch it in all 3 directions, that's the same as scaling it up. And the hollowing in Blender is very impressive. But what I would do, if you just want to thicken parts of it, is download sculptris. It imports obj, and it has a tool called inflate. You can thicken up only the parts you want to thicken.

Thanks! I'll give that a try!

I think I understand what your problem is.

The model came from Autocad and so it has areas that are one polygon thick?

I dont think "stretching" will have the same effect as "extruding" those faces though.

You'll have to spend some time going through the model element by element, polygon by polygon, editing it and making sure the one polygon objects are made "solid".

I'm not sure there's any easier way to do it.

You could be right. This is hard work! one problem I get now is hollow profiles, eg a box section, where the wall thickness is just far too thin to print. Is there any program / filter that would simply remove any hidden / non visible geometry? It's only really the visible surface that I want, anything that is hollow inside in the model, I would be happy to have solid.

I've used (the shapeways recommended) Netfabb Studio to check models and fix some issues and its pretty good. Sometimes its hard to tell exactly what its fixing but I believe its removed interior faces. And I'm pretty sure it'll delete the "illegal" polys.

It can take a long time to move through a complex model fixing it by hand.

Thanks, but I had used Netfabb Studio and had the all ok. Uploads that had gone fine after that were then accepted as ok to print, but after some days I get the message that the members cant be printed as the wall thickness of hollow sections is tooo thin! I could edit one model for printing, but it would be very time consuming and I was hoping to find some quick workflow so I could do this often with various models. I'm fairly sure there must be a way to just select the visible surface and ignore the hidden detail. the cad models I look at are from 10-200m in full size, and I know that when reduced for models, if they are built up of hollow sections they will be very very thin wall sections. The internal detail just isn't worth having on such models, but a quick way to take an autodesk model to a miniature physical model would be awesome!

Without seeing your model, I take it that there must be a hole 'tunnel' joining the inside to the outside.
This is just a thought. Maybe if you delete this hole 'fill it', so the model still has an inside and outside. Export this as an STL. Shapeways will ignore the internal geometry and treat it as a a solid.