More Vertex Arrays Woes (will this never stop!!)

899

Author

March 04, 2004 11:01 AM

Wow, am I tired of trying to get this working... Maybe I''m mixing stuff, I don''t know. Here are 2 pics, the 1st one shows my renderer with a typical display list, the 2nd using Vertex Arrays. Code follows.

Sorry for the high compression, I just wanted to show that there seems to be something wrong with how texturing is being done, here is the rendering code:


glBindTexture(GL_TEXTURE_2D, TextureID);

glVertexPointer   ( 3, GL_DOUBLE, 0, VertexBuffer);
glTexCoordPointer ( 2, GL_DOUBLE, 0, TexBuffer);
glNormalPointer   ( GL_DOUBLE,    0, NormalBuffer);
	
size = NumFaces*3; // 3 Vertices per Face

glDrawElements(GL_TRIANGLES, size, GL_UNSIGNED_INT, FaceList);

You guys see anything wrong? Normals also seem to be failing, shadow doesnt fall on the model correctly...

[Hugo Ferreira][Positronic Dreams][Colibri 3D Engine][Entropy HL2 MOD]
[Yann L.][Enginuity] [Penny Arcade] [MSDN][VS RoadMap][Humus][BSPs][UGP][NeHe]
"I say we take off and nuke the entire site from orbit. It''s the only way to be sure."

[ Mercury - An OS on your Browser | Mercury on YouTube ]

paulc

132

March 04, 2004 11:12 AM

Not a lot of code to go on, but here are a few ideas. You are enabling all the correct arrays with glEnableClientState() and when you setup the texcoord array you are using glClientActiveTexture() to specify the texture unit the coords should be used for client side, rather than server side with glActiveTexture for actual texture binding?

glActiveTexture( GL_TEXTURE0 );glBindTexture(GL_TEXTURE_2D, TextureID);glEnableClientState( GL_VERTEX_ARRAY );glEnableClientState( GL_NORMAL_ARRAY );glEnableClientState( GL_TEXTURE_COORD_ARRAY );glVertexPointer   ( 3, GL_DOUBLE, 0, VertexBuffer);glClientActiveTexture( GL_TEXTURE0 );glTexCoordPointer ( 2, GL_DOUBLE, 0, TexBuffer);glNormalPointer   ( GL_DOUBLE,    0, NormalBuffer);size = NumFaces*3; // 3 Vertices per FaceglDrawElements(GL_TRIANGLES, size, GL_UNSIGNED_INT, FaceList);// and disable all the arrays as appropriate with glDisableClientState

[edited by - paulc on March 4, 2004 12:24:05 PM]

SoDdit

157

March 04, 2004 11:19 AM

the way i did it was to have a VERTEX struct and use an array of those to hold the data

struct VERTEX{    flaot x, y, z; // The untransformed position for the vertex.    float nx,ny,nz;    DWORD color;        // The vertex color.    float tu,tv;};glNormalPointer(GL_FLOAT,sizeof(VERTEX),&verts[0].nx);glTexCoordPointer(2,GL_FLOAT,sizeof(VERTEX),&verts[0].tu);glVertexPointer(3,GL_FLOAT,sizeof(VERTEX),verts);glColorPointer(3,GL_UNSIGNED_BYTE,sizeof(VERTEX),&vert[0].color);glDrawElements(GL_TRIANGLES,m_noTris*3,GL_UNSIGNED_INT,tris);

where tris is a DWORD array of size m_noTris*3

i is 1337

Prozak

899

Author

March 04, 2004 11:29 AM

Thanks guys, dumb question, in which header can I find glClientActiveTexture? And how does it work, does it limit my texture options?

Thanks for any tips on this...

[Hugo Ferreira][Positronic Dreams][Colibri 3D Engine][Entropy HL2 MOD]
[Yann L.][Enginuity] [Penny Arcade] [MSDN][VS RoadMap][Humus][BSPs][UGP][NeHe]
"I say we take off and nuke the entire site from orbit. It''s the only way to be sure."

[ Mercury - An OS on your Browser | Mercury on YouTube ]

paulc

132

March 04, 2004 11:41 AM

glClientActiveTexture should be in an uptodate version of gl.h. It functions just the same as glActiveTexture, but on the client side, e.g. it does the same thing but for gl commands that are not executed immediately (I think this just applies to glTexCoordPointer calls, can''t think of anything else that uses it) - they are batched up and executed when the DrawElements or similar function is called. Okay, so it may be a bit misleading, in that the TexCoordPointer call is executed; the pointer is setup, but the data is just copied to where gl can access and use it rather than actually being drawn immediately.

Prozak

899

Author

March 04, 2004 12:20 PM

Ok, I have those 2 functions (glActiveTextureARB & glClientActiveTextureARB) in my GLCaps class that detects and assigns opengl extensions. My revised code looks like this now, but the results i get are still equal to pic 2...

glEnableClientState(GL_VERTEX_ARRAY);glEnableClientState(GL_TEXTURE_COORD_ARRAY);			GLCaps.glActiveTextureARB( GL_TEXTURE0);glBindTexture(GL_TEXTURE_2D, TextureID);glTexCoordPointer ( 2, GL_DOUBLE, 0, TexBuffer);glVertexPointer   ( 3, GL_DOUBLE, 0, VertexBuffer);GLCaps.glClientActiveTextureARB( GL_TEXTURE0 );size =   NumFaces*3;  // 3 vertices per FaceglDrawElements(GL_TRIANGLES, size, GL_UNSIGNED_INT, FaceList);glDisableClientState(GL_TEXTURE_COORD_ARRAY);glDisableClientState(GL_VERTEX_ARRAY);

[Hugo Ferreira][Positronic Dreams][Colibri 3D Engine][Entropy HL2 MOD]
[Yann L.][Enginuity] [Penny Arcade] [MSDN][VS RoadMap][Humus][BSPs][UGP][NeHe]
"I say we take off and nuke the entire site from orbit. It''s the only way to be sure."

[ Mercury - An OS on your Browser | Mercury on YouTube ]

Prozak

899

Author

March 04, 2004 01:07 PM

Another question,
When we define normals and texture coords, we define them allways by vertex, never by face, right?

I don''t think we can define texture coordinates UV for a face, but we can define the normals of a face with XYZ, or per vertex...

So our normals, texture coordinates are allways defined by vertex, right?

[Hugo Ferreira][Positronic Dreams][Colibri 3D Engine][Entropy HL2 MOD]
[Yann L.][Enginuity] [Penny Arcade] [MSDN][VS RoadMap][Humus][BSPs][UGP][NeHe]
"I say we take off and nuke the entire site from orbit. It''s the only way to be sure."

[ Mercury - An OS on your Browser | Mercury on YouTube ]

paulc

132

March 04, 2004 01:48 PM

The ClientActiveTexture call should go just before the TexCoordPointer call, its performing the same operation as ActiveTexture before a BindTexture call.

psamty10

148

March 04, 2004 01:53 PM

quote:Original post by pentium3id
Another question,
When we define normals and texture coords, we define them allways by vertex, never by face, right?

I don''t think we can define texture coordinates UV for a face, but we can define the normals of a face with XYZ, or per vertex...

So our normals, texture coordinates are allways defined by vertex, right?

By convention, all data is stored in the vertices and the face description then becomes a list of vertices in that face.
So yes, all normals and texture coords should be stored in the verts. As you correctly pointed out, there is no logical representation to map textures to a face.

Prozak

899

Author

March 04, 2004 01:56 PM

Thanks paulc, still unsuccessful, current code:

GLCaps.glActiveTextureARB( GL_TEXTURE0);glBindTexture(GL_TEXTURE_2D, TextureID);glEnableClientState(GL_VERTEX_ARRAY);glEnableClientState(GL_TEXTURE_COORD_ARRAY);glVertexPointer   ( 3, GL_DOUBLE, 0, VertexBuffer);GLCaps.glClientActiveTextureARB( GL_TEXTURE0 );glTexCoordPointer ( 2, GL_DOUBLE, 0, TexBuffer);size= FaceNum*3;glDrawElements(GL_TRIANGLES, size, GL_UNSIGNED_INT, FaceList);glDisableClientState(GL_TEXTURE_COORD_ARRAY);glDisableClientState(GL_VERTEX_ARRAY);

...Also, do I really have to do glEnableClientState, or can I do it once, at program initialization? Cause I''m currently doing it once per frame...

psamty10, thanks for clearing that up.

[Hugo Ferreira][Positronic Dreams][Colibri 3D Engine][Entropy HL2 MOD]
[Yann L.][Enginuity] [Penny Arcade] [MSDN][VS RoadMap][Humus][BSPs][UGP][NeHe]
"I say we take off and nuke the entire site from orbit. It''s the only way to be sure."

[ Mercury - An OS on your Browser | Mercury on YouTube ]

More Vertex Arrays Woes (will this never stop!!)

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