Difference between revisions of "Mesh"

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(Added information about inside points from http://my.bzflag.org/bb/viewtopic.php?p=139382#p139382. Note to Admins: File Uploader does not work due to the upload directory not being writable. Image should be uploaded once this issue is fixed.)
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  end #mesh
 
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==Inside Points==
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An inside point allows the mapper to make a mesh solid. This means that regardless of what the player tries to do, they will not be able to go through the object, or end up spawning inside a mesh unintentionally. When you drive through a box, especially with the Oscillation Overthruster flag, you will be inside of a building and sealed to it. Without inside points, especially to larger meshes, you will just end up on the inside of it and be able to shoot and drive normally. This is sometimes intentional, but usually not wanted. Inside points remedy this.
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In order to have successful inside point coverage, you need to make sure all faces of your mesh are in "line of sight" to the point you specify. This means that all faces have direct vision to that point, just as if that point was a point of light and all the faces were eyes. Only what can be seen through a straight line will be considered the inside for that face.
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Illustration is better than words, here is an image drawn up by '''Spazzy McGee''' from the forums.
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http://img205.imageshack.us/img205/2140/insides.jpg
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(Original forum post http://my.bzflag.org/bb/viewtopic.php?p=139382#p139382)
  
 
==Editor Support==
 
==Editor Support==

Revision as of 19:31, 20 October 2011

A mesh is a BZW map object that defines an arbitrary three dimensional shape. A mesh is defined as a series of faces containing 3 or more points(vertices) in three dimensional space.

Code

The code for a mesh object is as follows, this is only an example

mesh
 name example_mesh
   #
   # Material properties and physics applied to a mesh apply to all faces
   # that follow the setting. Mesh faces will alter their own
   # properties without affecting the state of the mesh properties.
   #
 inside 5.5 4.5 1.2 # add an inside point (repeatable) 
 outside 0 0 1000 # add an outside point (repeatable) 
 vertex 100 200 300 # add a vertex (repeatable) 
 normal 1.0 0 0 # add a normal (repeatable) 
 texcoord 0.1 0.75 # add a texture coordinate (repeatable) 
 shift 0 0 0 # (repeatable) 
 scale 1 1 1 # (repeatable) 
 shear 0 0 0 # (repeatable) 
 spin angle nx ny nz # (repeatable) 
 phydrv example_phydrv # assign a physics driver 
 smoothbounce # ricochets use normals 
 noclusters # render each mesh face individually 
            # (this can be useful for occluders) 
 face # start a face (repeatable) 
      # faces must be convex polygons 
   vertices 1 4 0 3 5 # list of vertices (requires at least three) 
   normals 2 6 0 4 7 # list of normals (optional) 
   texcoords 0 3 2 4 9 # list of texture coordinates (optional) 
   phydrv example_phydrv # assign a physics driver 
   smoothbounce 
   noclusters 
   drivethrough 
   shootthrough 
   passable 
   matref 
 endface # end the face 
  #
  #  The drawInfo element can be added to increase the rendering speed
  #  of the mesh object. If the client is capable of using this data,
  #  then it is used to draw the mesh instead of the face  information.
  #
end	  # mesh

Valid parameters for a mesh are

name The name of the mesh
vertex this is a 'corner' of your mesh - a point where faces connect. (at least 3 are required)
normal a unit vector describing the direction light will reflect off the object
texcoord this is used for mapping textures onto the mesh. This will link a point of the 2-Dimensional texture to a vertex on the 3-Dimensional object. (0,0) refers to the lower left corner of the texture, (1,1) refers to the top right. Textures are defined in the material object.
inside an arbitrary vertex placed on the inside of the mesh object. This keeps tanks from driving or spawning inside the object.
phydrv Assign a physics driver as defined in the physics object.
smoothbounce shot will ricochet from the face in the same direction as the defined normal.
noclusters Render each face individually.
shift places the mesh using <x y z> coordinates
scale resizes the mesh along the x, y, or z axis
shear repeatable
spin spins the mesh <angle> number of degrees, <n> number of rotations along one or more of the x, y, or z axis
drivethrough Tanks can drive through this mesh.
shootthrough Tanks can shoot through this mesh.
passable Tanks can both shoot and drive through this mesh
matref Assign a material to all below faces.
face Start a face (required), see below:

Valid parameters within the face sub-object:

vertices Numbered list of vertices for this face. (requires at least three)
normals Numbered list of normals for this face.
texcoords Numbered list of texture coordinates for this face.
phydrv Assign a physics driver to this face only.
smoothbounce use normals to determine shot ricochets for this face.
drivethrough Tanks can drive through this face.
shootthrough Tanks can shoot through this face.
passable Tanks can both shoot and drive through this face
matref Assign a material to this face.

Meshes have full support for Material (wherein custom textures can be defined) and Physics Drivers.

DrawInfo

DrawInfo can be added to the mesh object to increase rendering efficiency, allowing the designer to specify which details will be seen from certain distances. It can also be used to rotate a mesh object, though tanks can not interact with the moving object.

Appearance

The shape of a mesh will vary greatly as by its very nature it can be defined to look like anything. Unless a material is defined and applied, the default "mesh.png" texture will be applied to all faces of the mesh.

Simplified Examples

Simple Cube
mesh
   vertex -10 -10  0
   vertex  10 -10  0
   vertex  10  10  0
   vertex -10  10  0
   vertex -10 -10 10
   vertex  10 -10 10
   vertex  10  10 10
   vertex -10  10 10
   face #south
       vertices 0 1 5 4
   endface
   face #east
       vertices 1 2 6 5
   endface
   face #north
       vertices 2 3 7 6
   endface
   face #west
       vertices 3 0 4 7 
   endface
   face #bottom
       vertices 0 1 2 3
   endface
   face #top
       vertices 4 5 6 7
   endface
end #mesh
Simple billboard with texcoords
mesh 
   vertex -10 0  0
   vertex  10 0  0
   vertex  10 0 10
   vertex -10 0 10
   texcoord 0 0
   texcoord 1 0
   texcoord 1 1
   texcoord 0 1
   matref myBillboard
   face
       vertices 0 1 2 3
       texcoords 0 1 2 3
   endface
   face #backside
       vertices 1 0 3 2
       texcoords 1 0 3 2
   endface
end #mesh
Simple Jump-through floor
mesh
   vertex  0  0  9
   vertex 10  0  9
   vertex 10 10  9
   vertex  0 10  9
   vertex  0  0 10
   vertex 10  0 10
   vertex 10 10 10
   vertex  0 10 10
   face #south
       vertices 0 1 5 4
       drivethrough
   endface
   face #east
       vertices 1 2 6 5
       drivethrough
   endface
   face #north
       vertices 2 3 7 6
       drivethrough
   endface
   face #west
       vertices 3 0 4 7 
       drivethrough
   endface
   face #bottom
       vertices 0 1 2 3
       drivethrough
   endface
   face #top
       vertices 4 5 6 7
   endface
end #mesh

Inside Points

An inside point allows the mapper to make a mesh solid. This means that regardless of what the player tries to do, they will not be able to go through the object, or end up spawning inside a mesh unintentionally. When you drive through a box, especially with the Oscillation Overthruster flag, you will be inside of a building and sealed to it. Without inside points, especially to larger meshes, you will just end up on the inside of it and be able to shoot and drive normally. This is sometimes intentional, but usually not wanted. Inside points remedy this.

In order to have successful inside point coverage, you need to make sure all faces of your mesh are in "line of sight" to the point you specify. This means that all faces have direct vision to that point, just as if that point was a point of light and all the faces were eyes. Only what can be seen through a straight line will be considered the inside for that face.

Illustration is better than words, here is an image drawn up by Spazzy McGee from the forums.

http://img205.imageshack.us/img205/2140/insides.jpg

(Original forum post http://my.bzflag.org/bb/viewtopic.php?p=139382#p139382)

Editor Support

The mesh object is supported by the BZWTools blender plugin, the Wings3D Exporter and hand coding.

History

The Mesh object was added with the v2.0.0 release of BZFlag.