Painting an Entity

I have been experimenting with creating a "door" mesh for a dungeon. I selected a nice wood texture to color it, but when I display the door, it just shows up as a gray color, not the vivid browns of the wood texture. What am I missing? What's the proper procedure for "painting" a mesh you have created. Hey, BTW, is there anyway to save meshes created inside Blitz3D, so they can just be loaded off a harddrive?

I'm guessing you haven't set UV coordinates for your vertices. UV coordinates let the rendering engine know what parts of your textures get painted where on your mesh.

Yes you can save meshes - look in the code archives there are a few different formats that you can export to. Although I don't think it is possible using blitz commands alone to create bones so animated b3d models are not possible, I think.

Here are some of the code archive links:

ASC format:

http://www.blitzbasic.com/codearcs/codearcs.php?code=1033

B3D format:

http://www.blitzbasic.com/codearcs/codearcs.php?code=866

VRML format:

http://www.blitzbasic.com/codearcs/codearcs.php?code=580

DirectX format:

http://www.blitzbasic.com/codearcs/codearcs.php?code=631



Oh..and regarding the first question - yes you need to set the UV coordinates on each vertex of your mesh.

Hate to admit it, but while I am fairly practiced at 2D programming, this is my newbie attempt at Blitz3D. So, ummm, how do I set the UV coordinates?

I have created a mesh and one surface (do I need to create a separate surface for each side of the door?) and eight vertices, and have created 12 triangles (for the six sides of the door). How do I set UVs for these? Thanks.

(Oh, and thanks for the info on saving meshes!)

Use the VertexTexCoords command to set the UVs.

Well, the command says:
VertexTexCoords surface,index,u#,v#[,w#][,coord_set]
Parameters
surface - surface handle
index - index of vertex
u# - u# coordinate of vertex
v# - v# coordinate of vertex
w# (optional) - w# coordinate of vertex
coord_set (optional) - co_oord set. Should be set to 0 or 1.

Description
Sets the texture coordinates of an existing vertex.


So, what are u# and v# and w# coordinates? How are they expressed? What info should I be supplying to the command to accommodate it?

First of all, forget about the w# coord - it's not used. Also, forget about the coord_set for now as this is only used for multi-texturing.

The u and v coords specify the horizontal and vertical coords of the texture to map to the vertex. However, these coords aren't expressed as pixel positions, they're a decimal fraction in the range 0.0 to 1.0. So, the top-left of the texture is u=0,v=0 and the bottom-right is u=1,v=1. Crappy ASCII art coming up:

  0       U coord      1
0 ----------------------
  |                    |
  |                    |
V |                    |
  |                    |
c |                    |
o |      Texture       |
o |                    |
r |                    |
d |                    |
  |                    |
  |                    |
1 |____________________|

That's probably as clear as mud so you're probably better off googling for a better explanation of how UV mapping works. :)

Here you go.


This image shows pretty much what big10p said, I highlighted one of the UV co-ordinates which is shown in red, the co-ordinates for it are at the bottom of the image (ignore the W co-ordinate).

Basically you have a texture, then you move the vertices of the parts of model to fit to it.

Hope that helps. =)

Most definitely interesting. Thanks. What application are you using for that dartboard pic?

For what it's worth, I worked around the door by simply using CreateCube()., then ScaleMesh to reshape it, and then textured it, and voila! I have a door.

That screenshot is from Max 6. I haven't tried messing about with UV's in Blitz yet. I will do one day though.

I've been looking up the price on 3d max. Holy smoke! That's one expensive software package, and out of my cost budget.