Meshing basics.

[Tim Flynn]

I've decided to give Mesh a try recently, and am slowing chugging along in the tutorials.

Being new, i've spent most of my building life (and it's not that long)  using blocks and shapes to construct massive and fairly complicated structures that I thought Mesh might be better suited for, especially if these buildings are just backdrops or part of the scenery in 3D, versus actually livable and walk through structures.

So basically, i'm looking for the basics.  What can and can you not do with mesh, how big can you build and import in Mesh and why do you guys prefer mesh over building from scratch?

Any feedback is great.  I'm looking to learn:
1. How big of an import can I bring from Blender to SL?  Once it's in SL, can I resize and adjust as needed? It's one object right?

2. Can I actually create corridors and other complex rooms in my mesh?  Or will it just simply be a 3D building.  Scenery more or less?

3. After the mesh is build, can I add scripting to any of it?  Such as a blinking light on top of the tower or will I be forced to add it as a new prim.  

4. Can you tell the difference between Mesh and 

5. I understand they charge you depending on the size and complexity of the mesh.  Is there a maximum limit or does it just keep going up?
6. I understand that you can generally building bigger and better things with Mesh with less prims, than building it from scratch? Is this true?

7. What is the meaning of life (2nd). lol

8. Anything else you wish you knew as an aspiring mesh'r?

Thanks in advance!  Hope to become a good mesher!

[Drongle McMahon]

What can and can you not do with mesh,

You can do almost anything. You can't use flexi. You can't animate by switching the mesh geometry, but you can switch visibility of parts. Errmm....

how big can you build and import in Mesh and why do you guys prefer mesh over building from scratch?

Maximum x, y or z  dimension of a mesh is 64m. Mesh is building from scrathch. Other prims are ready-made parameterised meshes. Mesh gives you better render efficiency (mostly), better control over LOD changes and better texturing.

1. How big of an import can I bring from Blender to SL?  Once it's in SL, can I resize and adjust as needed? It's one object right?

For a single mesh prim, 64m (above). You can stretch and rotate the whole mesh in each dimension, limited by 64m maximum. You cannot use any other of the distortions available for ordinary prims. You can import multiple mesh prims in one upload. They will form either a single linkset object or a set of coalsced objects.

2. Can I actually create corridors and other complex rooms in my mesh?  Or will it just simply be a 3D building.  Scenery more or less?

Yes. You can make buildings that you can walk inside. To do so, you need to learn about making physics shapes, which is quite complicated.

3. After the mesh is build, can I add scripting to any of it?  Such as a blinking light on top of the tower or will I be forced to add it as a new prim.  

You can put scripts in mesh prims. They can change the texture and other properties of the faces, just as with ordinary prims. Each mesh can have up to eight faces/materials. Unlike ordinary prims, the faces can be made up of discontinous patches of the measj surface. You cannot change the geometry of the mesh with scripts although you can change the visibility of faces (with invisible textures) and the size of the whole thing.

4. Can you tell the difference between Mesh and 

and what?

5. I understand they charge you depending on the size and complexity of the mesh.  Is there a maximum limit or does it just keep going up?

I think the upload fee is not explicitly capped. There is a maximum complexity of 65536 vertices per material, but you would be most unwise to try to import anything remotely approaching that limit. Imports of very complex meshes well short of the limit generally fail for unknown reasons.

There is another accounting system which determines the "cost" of the meash against the parcel prim allowance. This is called the land impact. It depends on both visual complexity, physics representation and size. Learning to control the land impact is the major challenge of SL-specific mesh design.

6. I understand that you can generally building bigger and better things with Mesh with less prims, than building it from scratch? Is this true?

Those are subjective judgements depending on varying personal criteria. Many would say yes, but with a few exceptions.

7. What is the meaning of life (2nd). lol

42 vertices.

8. Anything else you wish you knew as an aspiring mesh'r?

Exactly how the server calculates physics weights.

 

[Tim Flynn]

Thank you for a timely reply.  What I meant by number 4 was the difference between mesh and building from scratch, but I think the question has been answered.  

[Vegro Solari]

If making buildings, towers and so on, don't shelf your  normal prim-building skills.. You may find that the best results (more prim efficient and less expensive)  will be gotten by using a combo of ordinary prims or sculpts to block in your general structure, plus using carefully placed mesh details.

 

That's important because when you start with meshes, you'll be horrified how much everything takes prim-wise, which used to be just one simple prim before!  Then you start trying to figure out how to out-trick the tricky mesh uploading system to do efficient meshes. But most of the time it's pretty tough to make things that can be as efficient as normal prims or sculpts. That's why the "combo approach" can be the best for fast/efficient builds.

A tricky thing to keep in mind when you work with mesh/sculpt/prim combos is that if you link any mesh to something that was only prims/sculpts before,  that makes SL consider the entire linkset as a mesh, for primmage calculation.  In some rare cases it actually helps, but it most, you end up with many times more prim cost than you could have if you just didn't link them!