uniform_patch_size = glGetUniformLocation(densify_program, "patch_size");
uniform_patch_spacing = glGetUniformLocation(densify_program, "patch_spacing");
uniform_image0_tex = glGetUniformLocation(densify_program, "image0_tex");
uniform_image1_tex = glGetUniformLocation(densify_program, "image1_tex");
uniform_flow_tex = glGetUniformLocation(densify_program, "flow_tex");
uniform_patch_size = glGetUniformLocation(densify_program, "patch_size");
uniform_patch_spacing = glGetUniformLocation(densify_program, "patch_spacing");
uniform_image0_tex = glGetUniformLocation(densify_program, "image0_tex");
uniform_image1_tex = glGetUniformLocation(densify_program, "image1_tex");
uniform_flow_tex = glGetUniformLocation(densify_program, "flow_tex");