Editing Mesh

[lui]

Hi

I know it sounds odd but lets say i have created a mesh in TV3D using vertices (like explained here http://wiki.truevision3d.com/tutorialsarticlesandexamples/building_a_cylinder)

Now I don´t only want to create a mesh but also want to edit it.
Is there a way to get a vertex from a specific position and move it to another?
The only way a figured out is to delete the old mesh and create a new one with the updated position of the vertex ( this is the way i saw it in another engine because there was no other way). But this would be computationally intensive and would take some time when there are alot of vertices.
So is it possible to only move a certain vertex?

Additionally is it possible to delete a vertex?

greetz
Lui

[Lenn]

You don't have to delete a mesh, just use .SetGeometry.

You can access any of the verts you have in the TV_SVERTEX array. Move them, and the mesh will change. You can also delete them, but then you will have to recreate the indices, and that is up to you to figure out really.

[sinisa1982]

So how can get position of the specific vertices ?

[Lenn]

They are all in the TV_SVERTEX array you set in the first place, isn't that obvious? Loop through each one, they all have their x,y,z components.

[asia]

What about getvertex and setvertex methods for meshes?
I did use them for the manta example in the WIKI.
Fabio

[Lenn]

Yes, I was talking about using the arrays which work with SetGeometry for easy editing and applying the changes. At least I think that's the easiest method.

[asia]

Some time ago I tried to edit a mesh after I loaded it with the loadtvm method.
The sistem crushed if I tried to add something, like a vertex or a triangle. Do you have any idea?
Example:

 Mesh.LoadTVM TVMname
 Mesh.addface 0 ' does not crash

 Mesh.AddVertex fx, fy, fz, fnx, fny, fnz, t1u, t1v, t3u, t3v, c ' crash
 Mesh.AddTriangle 0, 1, 1, 1, 0, 0, 0, 1, 0, 1 ' crash
Look also at:
http://www.truevision3d.com/forums/printpage.html;topic=18602.0
The same does not happen if you create the mesh from scratch (scene.createmeshbuilder)
Any suggestion will be appreciated.

[lui]

Thanks for the answere. This should do it somehow

@ asia:
This is explained also in the Doku(still 6.1 but seem to be still valid)

Code:

Remark:
You can't add a vertex to a loaded mesh or to a primitive mesh (made with CreateBox, CreateCylinder...)
You have to use the "point" primitive if you want to add points to this mesh

Got another, maybe stupid question:
when I e.g want to make a grid witch looks like this:


When i make this with trianglelist (like explained in the tutorial i linked to) I would only be able to make this grid row by row and the rown themselevs would be smooth but not among each other.
Also i would have to declare a vertex at the same position for more than one time, this would cost alot more memory usage.
So how could i just first store the vertices into to the TV_SVERTEX array without connecting them. And then connect e.g vertex[1] vertex[4] and vertex[23] to a polygon? When the polys would use the same vertex they should also be smooth...

Or does TV3D recognize that a vertex already exists at the position and uses this one for the new polygon?

greets lui

[asia]

Unfortunately the setvertex method in the mesh class doesn't support the extra parameter for “add point” in TV 6.5.
But isn’t it strange that you can not edit a loaded mesh? And even a bloody teapot?
I must miss something!
Help!
Fabio