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screen show nothing when using GL_FILL for evaluator

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I used the following code to show a 1/4 of a hollow cylinder lying along the z-axis. However, using GL_FILL i am able to see the mesh but nothing appear when i use GL_FILL. Need help urgently! //drawing surface (Curved) GLfloat ctrlPoints[3][3][3]={{{-d,0.0f,1.0f},{-0.9f*d,-0.9f*d,1.0f},{0.0f,-d,1.0f}}, //v=0 {{-d,0.0f,0.0f},{-0.9f*d,-0.9f*d,0.0f},{0.0f,-d,0.0f}}, //v=1 {{-d,0.0f,-1.0f},{-0.9f*d,-0.9f*d,-1.0f},{0.0f,-d,-1.0f}}};//v=2 // the setup function glMap2f(GL_MAP2_VERTEX_3, // Type of data generated 0.0f, // Lower u range 10.0f, // Upper u range 3, // Distance between points in the data 3, // Dimension in u direction (order) 0.0f, // Lower v range 10.0f, // Upper v range 9, // Distance between points in the data 3, // Dimension in v direction (order) &ctrlPoints[0][0][0]); // array of control points // Enable the evaluator glEnable(GL_MAP2_VERTEX_3); glEnable(GL_AUTO_NORMAL); glEnable(GL_NORMALIZE); // Map a grid of 100 points from 0 to 100 glMapGrid2f(10,0.0f,10.0f,10,0.0f,10.0f); // Evaluate the grid, using lines glEvalMesh2(GL_FILL,0,10,0,10); i set up my lightings in a function before this code so do not know what else is missing or incorrect. [edited by - coda_x on January 14, 2004 8:46:49 PM]

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What code do you use for drawing, i think the problem lies there, and, when lighting is disabled, is it visible then with GL_FILL?

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before the above code, i rendered other objects and they all appeared as expected and lighting was enabled in the beginning. the funny thing is, when i add another line: rotate by 180 abt y -axis such that it become mirror image, the surface works and appear but not when it is along the z-axis. Or could it be that the shape is already there but the somehow the lighting obscure it or something like that?

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