Jump to content
  • Advertisement
Sign in to follow this  
giugio

[c++]Collada and normals

This topic is 3632 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hy. In a collada file I have a poly(a cube)with 18 normal, i dont know how normal(face or vertex or..???) <source id="Cube-Geometry-Normals"> <float_array count="18" id="Cube-Geometry-Normals-array">0.00000 0.00000 -1.00000 0.00000 0.00000 1.00000 1.00000 -0.00000 0.00000 -0.00000 -1.00000 -0.00000 -1.00000 0.00000 -0.00000 0.00000 1.00000 0.00000</float_array> <technique_common> <accessor count="6" source="#Cube-Geometry-Normals-array" stride="3"> <param type="float" name="X"></param> <param type="float" name="Y"></param> <param type="float" name="Z"></param> </accessor> </technique_common> </source> and 4 index for face: <polygons count="6" material="Material"> <input offset="0" semantic="VERTEX" source="#Cube-Geometry-Vertex"/> <input offset="1" semantic="NORMAL" source="#Cube-Geometry-Normals"/> <input offset="2" semantic="TEXCOORD" source="#Cube-Geometry-UV"/>

0 0 0 1 0 1 2 0 2 3 0 3

4 1 4 7 1 5 6 1 6 5 1 7

0 2 8 4 2 9 5 2 10 1 2 11

1 3 12 5 3 13 6 3 14 2 3 15

2 4 16 6 4 17 7 4 18 3 4 19

4 5 20 0 5 21 3 5 22 7 5 23

</polygons> what kind of normals i have? Because i have 4 normal for face,I suppose that are vertex normals but if i have a normal for vertex i would have 24 normals(6*4 = 24) and i have only 18 normals. Thanks in advance.

Share this post


Link to post
Share on other sites
Advertisement
<accessor count="6" source="#Cube-Geometry-Normals-array" stride="3">

This tells you there are 6 normal vectors. Each normal vector has 3 components. The three components are:

<param type="float" name="X"></param>
<param type="float" name="Y"></param>
<param type="float" name="Z"></param>

The normals are stored in a float array. So the first normal is stored as the first three floats in the float array.

For the <polygons> you have, there are 6 of them, making 12 indices per polygon. Because you have 3 inputs (vertex,normal,tex), then that means the poygons are quads (12/3 = 4).

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!