OpenGL texture blending problem

Question

Hi,

I am trying color a wavefront OBJ 3D model using a PNG file on iPhone 3G. The model is superimposed on a background and the PNG file is extracted from the background image. I notice that the blending could be better, though the texture parameters seem to work fine. I have given the code below. Any pointers as to which other parameters I could use? Appreciate any help in this matter.

John

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glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE); 
glShadeModel(GL_SMOOTH);
....