Yes I suppose it doesn't. I came to believe that you cannot have your model's shading correct if you need to close your mesh. There is an option in med under the edit menu as "create groups".. it seemed to do what i required at first. When you choose some faces that needs to be in the same smoothing group and press the create group button, they are shaded equally - vertex normals are pointing at the same direction. but this again makes your mesh "open".

I tried what you suggested: but the problem is; this issue is not limited to corners that needs to be sharp. even a straight surface defined by 1 polygon )2 triangles) could be broken (shaded wrong) when i import into the med. What would you do in this situation? I mean if you were to go on with open meshes, do you have any idea that if the performance of the game will suffer greatly?

Thanks for the replies by the way, gratly appreciated!

Try Edit>Recalculate Model
This should fix smoothing artefacts.

unfortunately, it doesn't it straightens things a little bit, but not to a point that the model is the way it should be..

I sent you a PM with my email, send me the file and I will check. I made a simple box wit some extruded faces similar to your house and I didn't get those artifacts.

Hi,
if you follow those steps exactly it will work:

1. In max convert your mesh to editable poly to access advanced modeling features.

2. Select all edges you want to make sharp. Be sure not to select triangulation edges. In this case it could be annoying, perhaps it's better to remove the triangulation first.

3.Apply EXTRUDE with Height and Base With =0. Click the tiny button beside the Extrude button and a small menu will pop up where you can type the values by hand.

4.Export. Be sure your exporter doesn't merge close vertices. I used Obj.

5.Import to MDL. Your mesh now should be closed with sharp edges.

If there are still artifacts, you accidentally extruded a wrong edge.

sorry man, I couldnt get it working... i already start modeling in the poly mode, then convert to the mesh. Triangulation is something that i have added later.
[by the way: Do you believe that it can be skipped? (I am not sure of triangulation since it increases the poly count, but gets rid of some sharp triangles(gives you control over the how those triangles are produced..)]

I did extrude the edges and exported as 3ds but after importing to the med and merging the vertices, still, the same problem persists. And I dont see how this method will improve the wrong shading of the smooth surfaces. When I export as obj it seems that the vertices weld (the model is closed) but the smoothing groups are messed up (I am checking this with another program (deep exploration)since I alsın coulnt import those objs into med there seems to be problem with the normals...) but still no results for me thanks for trying though. Would you mind sending your working obj or 3ds files to me? Maybe it will show me what i am missing..

But if I dont merge the vertices it wouldnt be a close mesh, would it? (Mesh tester in gamestudio will say that it is open) Do you mean that I do not need close meshes anyway?

If you want to use the stencil shadow then you need closed meshes. Otherwise it will be ok.

But you can have sharp edges with very small extrusions. The vertices just should not have same coordinates.

When I import it is closed as it should be.