views:

37

answers:

2

I want to draw car in my world. but i have problem with lighting when my car rotate ,it seems light position change when car is rotating; but when i draw simple cube with glut function it work correctly.

void mydisplay(){

glLoadIdentity()
glDisable(GL_LIGHT0);
glColorMaterial ( GL_FRONT_AND_BACK, GL_DIFFUSE) ;
glColor3f(1.0,1.0,1.0);
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
p2[0]=50.0;
p2[1]=3.0;
p2[2]=0.0;
glLightfv(GL_LIGHT0,GL_POSITION,p2);
glEnable(GL_LIGHT0);
gluLookAt(50.0,3.0,0.0,0.0,0.0,0.0,0.0,1.0,0.0);
glPushMatrix();
glRotatef(tet,0.0,1.0,0.0);
glutSolidCube(20);
glPopMatrix();
tet+=3.141592653/4;
glutSwapBuffers();

}

when glutSolidCube(20); change to my drawing code,it work in bad way my code:

void Drawing(){

glEnableClientState(GL_VERTEX_ARRAY);
GLfloat CubeVertex[]={  -20.0,0.0,10.0,//\/\/\/\/\/\\\///\/\/\/\/\/\/\/\/\/\/\/\/\/\/
                -20.0,0.0,-10.0,
                -20.0,3.0,-10.0,
                -20.0,3.0,10.0,    ///BIG   CUBE
            20.0,0.0,10.0,
            20.0,0.0,-10.0,
            20.0,3.0,-10.0,
            20.0,3.0,10.0,////////\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
            -10.0,3.0,10.0,
            -10.0,3.0,-10.0,
            -10.0,5.0,-10.0,
            -10.0,5.0,10.0,     //SMALL  CUBE
            10.0,3.0,10.0, 
            10.0,3.0,-10.0,
            10.0,5.0,-10.0,
            10.0,5.0,10.0,//\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\//
            -100.0,-2.4,100.0,
            -100.0,-2.4,-100.0,      //FLOOR
            100.0,-2.4,100.0,
            100.0,-2.4,-100.0
            };//\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\\/\//
GLubyte big_back[]={0,3,2,1};
GLubyte big_front[]={4,5,6,7};
GLubyte big_left[]={4,0,3,7};
GLubyte big_right[]={1,2,6,5};
GLubyte big_up[]={2,3,7,6};
GLubyte big_down[]={0,1,5,4};
GLubyte small_back[]={9,10,11,8};
GLubyte small_front[]={12,13,14,15};
GLubyte small_left[]={8,11,15,12};
GLubyte small_right[]={9,10,14,13};
GLubyte small_up[]={10,11,15,14};
GLubyte floor[]={16,17,19,18};
GLsizei count[]={4,4,4,4,4,4,4,4,4,4,4,4};
GLvoid* indices[12]={big_back,big_front,big_left,big_right,big_up,big_down,small_back,small_front,small_left,small_right,small_up,floor};
glVertexPointer(3,GL_FLOAT,0,CubeVertex);
for(int i=0;i<12;i++){//////////////////glMultiDrawElement////////////////
if(count[i]>0)
    glDrawElements(GL_QUADS,count[i],GL_UNSIGNED_BYTE,indices[i]);
}//////////////////////////////glMultiDrawElements//////////////////////

}

Thank you.

+1  A: 

You can find the answer here: http://www.opengl.org/resources/faq/technical/lights.htm section: 18.050 How can I make my light move or not move and control the light position?

Felics
A: 

I said that my code work correctly with glutSolidCube(20) but have problem with glDrawElements .why?

Thanks.

pooya