Q:

OpenGL and GL_Blend with glDrawElements

Solved by adding glDepthFunc(GL_ALWAYS);
I'm trying to blend two textures on a heightfield with glDrawElements.  Normalpointer and vertexpointer data are the same but the TexCoordPointer are different for the two textures.  No matter which BlendFunc I try there's always only one of the textures visible although large parts of texture_two are transparent.  Does glDrawElements work with gl_blend or am I doing it wrong? 
glEnable(GL_BLEND);
glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
glBlendEquation(GL_FUNC_ADD);
glDepthFunc(GL_ALWAYS);

glNormalPointer(GL_FLOAT, 0, normals);
glVertexPointer(3, GL_FLOAT, 0, vertices);

glTexCoordPointer(2, GL_FLOAT, 0, texture_ind_one);
glBindTexture(GL_TEXTURE_2D, texture_one);
glDrawElements(GL_TRIANGLES, indicies_num, GL_UNSIGNED_INT, indices);

glNormalPointer(GL_FLOAT, 0, normals);
glVertexPointer(3, GL_FLOAT, 0, vertices);

glTexCoordPointer(2, GL_FLOAT, 0, texture_ind_two);
glBindTexture(GL_TEXTURE_2D, texture_two);
glDrawElements(GL_TRIANGLES, indicies_num, GL_UNSIGNED_INT, indices);

Thank you very much! 

A:

You need to set an appropriate depth function via glDepthFunc using something that has "equals" in it (probably GL_LEQUAL), since you are drawing twice at the same depth. 
You can also consider blending the textures yourself inside a fragment shader.