Do you need vertex normals?

[Marcel]

The re-smoothing of imported CAD models is really evil, but it is not a problem of Max lacking vertex normals.
Max does have vertex normals, but you never notice them as such. (when you do stuff with Maxscript you have to adress normals by vertices, that's when I first learned that it's the vertices having normals, and not the faces as I thought)

Seems like the CAD import utility comes from the stoneage anyway. I remember having to wait hours for the darn thing to import the whole drawing :)

[DIMO]

Hi,

It's right that you can adress the vertex normals with maxscript, but try the following: Make a box, collapse it, set a normal with setnormal() , save the file, reload it -> Your changes are gone!

The reason for this is, that the editmesh class does not save the data of the vertexnormals. It is always recomputed. You can find the relevant SDK function under BuildNormals() in the SDK. Almost every modifier will call it, so your changes with maxscript wouldn't even survive a uvwmap.
This means that the RVertex and RNormal classes that can be found in the SDK are not saved with the mesh. I'm currently digging in the SDK very deep to find a workaround and I have talked to various developers. It seems the only solution is to write a new meshclass that prevents the recomputing of the normals.

Writing an importer that sets the normals right would be easy, but there's nothing that you could set, because the normals are always recomputed.

[LFShade]

That being the case, one has to wonder why they would expose vertex normals as read/write in Maxscript. Strange:shrug:

RH

[JHN]

Hi,
maybe this plugin is what you need: Mesh Army Knife;
http://www.phoenixgrafik.de/coding/meshak.htm

bottom page says:
# Norm by pivot:
This sets the type of normal. If switched off, the real vertex/face/poly normal is used. This has the problem, that the normals constantly change, if they are not locked (see below). If switched on, not the real normal is used, but a line from the pivot point through the vertex/face/poly. This has the advantage, that these "normals" doesn't change, when you paint on the mesh. Additionally, you can influence the direction by moving the pivot.
# Lock Normals:
Locks the normals in their current state. The normals are frozen in its current state - no matter how much you paint, they stay the same.
# Save/Load Normals:
I have to confess, that this option is not very useful. You may save and load the normals of the current mesh, but loading the normals is only possible into the same mesh, without any vertex or face changes (adding/deleting verts and faces).

Don't think it's exactly what you need, but maybe this helps,
Grtz JHN

[fenix]

Mesh Army Knife can't be a solution for this. The normals stated in the quoted part of the manual are just temporarily normals, used as a direction vector for deform paint on a mesh. They haven't got anything to do with render normals, sorry.
bye
phoenix

[JHN]

Yeah I thought so, but maybe it could give some pointers of what to do next.

JHN

[DIMO]

I was already in contact with Phoenix (the authorof Mesh AK), and he also has no "easy" solution for this.

[DIMO]

Just a sidenote:

If you wonder what we do with CAD data look at this:

http://www.cgtalk.com/showthread.php?s=&threadid=63514&perpage=15&pagenumber=1

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