OpenGL ES (displaying model)

Member

Posts: 35
Joined: 2008.06

Post: #1

Aug 10, 2008 — 08:57 PM

I have loaded and displayed an wavefront .obj model in OpenGL perfectly, but the same model displays crazy in OGL ES. It is missing polygons, like there are triangles missing or being connected incorrectly. Culling is not turned on. The same code works perfectly in OpenGL.

Does anybody else have this problem. Here is the rendering source using vertex arrays:

Code:

glEnableClientState(GL_VERTEX_ARRAY);                    

            glVertexPointer(3, GL_FLOAT, 0, va_verts);

            if ( numNormals > 0 ) {

                glNormalPointer(GL_FLOAT, 0, va_norms);

                glEnableClientState(GL_NORMAL_ARRAY);

            }

            if ( numTexCoords > 0 ) {

                glTexCoordPointer(2, GL_FLOAT, 0, va_textures);

                glEnableClientState(GL_TEXTURE_COORD_ARRAY);

            }

            glDrawElements(GL_TRIANGLES, numTriVerts, GL_UNSIGNED_SHORT, va_indices);            

            glDisableClientState(GL_VERTEX_ARRAY);

            glDisableClientState(GL_NORMAL_ARRAY);

            glDisableClientState(GL_TEXTURE_COORD_ARRAY);

green_ghost

Member

Posts: 35
Joined: 2008.06

Post: #2

Aug 12, 2008 — 04:51 PM

I'll reply to my own post, it may help someone.

Looks like glDrawElements wants the triangles to be connected together, and in a particular order. So for now I am going to use glDrawArrays, though eventually will SEEK :

something more efficient.

Code:

glPushMatrix();

        glTranslatef(0, 0.45f, 0);

        glEnableClientState(GL_VERTEX_ARRAY);

        glVertexPointer(3, GL_FLOAT, 0, a_vertData);

        glEnableClientState(GL_TEXTURE_COORD_ARRAY);

        glTexCoordPointer(2, GL_FLOAT, 0, a_texData);

        for (i=0; i < a_facesCount; i++) {

            glDrawArrays(GL_TRIANGLES, (i * 3), 3);

        }

    glPopMatrix();

codetiger

Apprentice

Posts: 5
Joined: 2008.10

Post: #3

Oct 14, 2008 — 07:10 AM

Hi green_ghost,
Did the 2nd code solve your problem? I am still struggling with the same problem like how you said.

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