Here is the final render of glass shaded in maya

step-1- Take a glass model, create a plane and a sphere for applying HDRI image as u can see the image below.

step2- GO to window- rendering editor – Hypershade and take a Sampler info ,Ramp and a Phong.


Step3- Now select Ramp and assign two colors to it . white above and grey down .

Step4- Drag the ramp to reflectivity of the Phong. Make the transparency color white and color to light grey.

Step5- drag the Sampler info to ramp( by middle mouse button) click on other, connection editor will open then choose Facing ratio(output) and go inside uv coordinate- select v coordinate(inputs)
u can see the image below

Step6- Take a new file and apply an HDRI image to it and assign this image to the sphere we made( for the environment).

Step7- Go to render settings- Render using – Mental ray
choose Sampler mode to Adaptive Sampling
On Raytracing – reflections-10, refractions – 20 , max trace depth – 20

step8- create a directional light if needed. Now hit the Render and enjoy!!!