TextureMatrix

cusTom3 · **Posted:** Mon Jun 20, 2005 11:19 pm

i am trying to understand idMapBrushSide in an effort to analyze .map files... :roll:

what is a TextureMatrix?

in idMapBrushSide:

Code:

class idMapBrushSide {
   friend class idMapBrush;

public:

   const char *         GetMaterial( void ) const { return material; }
   void               SetMaterial( const char *p ) { material = p; }
   const idPlane &         GetPlane( void ) const { return plane; }
   void               SetPlane( const idPlane &p ) { plane = p; }
   void               SetTextureMatrix( const idVec3 mat[2] ) { texMat[0] = mat[0]; texMat[1] = mat[1]; }
   void               GetTextureMatrix( idVec3 &mat1, idVec3 &mat2 ) { mat1 = texMat[0]; mat2 = texMat[1]; }
   void               GetTextureVectors( idVec4 v[2] ) const;


protected:
   idStr               material;
   idPlane               plane;
   idVec3               texMat[2];
   idVec3               origin;
};

I have looked at how it is stored:

Code:

brushDef3
 {
  ( 0 0 -1 0 ) ( ( 0.015625 0 0 ) ( 0 0.015625 0 ) ) "textures/base_floor/a_diafloor_1b_fin" 0 0 0
  ( 0 0 1 -8 ) ( ( 0.015625 0 0 ) ( 0 0.015625 0 ) ) "textures/base_floor/a_diafloor_1b_fin" 0 0 0
  ( 0 -1 0 -32 ) ( ( 0.015625 0 0 ) ( 0 0.015625 0 ) ) "textures/base_floor/a_diafloor_1b_fin" 0 0 0
  ( 1 0 0 -40 ) ( ( 0.015625 0 0 ) ( 0 0.015625 0 ) ) "textures/base_floor/a_diafloor_1b_fin" 0 0 0
  ( 0 1 0 -32 ) ( ( 0.015625 0 0 ) ( 0 0.015625 0 ) ) "textures/base_floor/a_diafloor_1b_fin" 0 0 0
  ( -1 0 0 -16 ) ( ( 0.015625 0 0 ) ( 0 0.015625 0 ) ) "textures/base_floor/a_diafloor_1b_fin" 0 0 0
 }

and i understand how it is parsed. but i don't get what it represents?

the only thing i can find is:

Code:

   // read the texture matrix
   // this is odd, because the texmat is 2D relative to default planar texture axis

      if ( !src.Parse2DMatrix( 2, 3, side->texMat[0].ToFloatPtr() ) ) {
         src.Error( "idMapBrush::Parse: unable to read brush side texture matrix" );
         sides.DeleteContents( true );
         return NULL;
      }

thanks for any ideas?

der_ton · **Posted:** Tue Jun 21, 2005 4:06 pm

It's a 2x2 matrix that the UV coordinates of the brush are transformed with. So it controls the rotation and scale of the texture on that brush side.

cusTom3 · **Posted:** Tue Jun 21, 2005 4:45 pm

i see

thanks der_ton.

binaryc · **Posted:** Wed Jun 22, 2005 5:46 pm

it's actually a 3 x 2 matrix.

pha3z · **Posted:** Mon Aug 22, 2005 6:27 am

Would it be possible to store more than one set of UV Coordinates on a brush and then specify which coordinates you want to use for mapping a texture in a shader file?

Example use: Applying a material to a brush that blends two textures where each texture is mapped with different coordinates.

Doom3world

TextureMatrix

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