Create simple scene with sphere and light
Check normal direction of your glass object. p_MegaTK is sensitive to normal during computing reflect/refract.
Assign p_MegaTK to sphere

Simple Scene
Set following attributes in p_MegaTK shader:
- 'Use Reflection' = On
- 'Coefficient Reflection' = 1
- 'Use Refraction' = On
- 'Coefficient Refraction' = 1
And check 'Fresnel' value should be 1(by default)
Set appropriate IORs. For example for glass it should be 'IOR_in' = 1.5 and 'IOR_out' = 1.0
Open Render Settings and set followed parameters in Raytracing tab:
- 'Reflection' = 3
- 'Refraction' = 3
- 'Max Trace Depth' = 5
- 'Shadow' = 3
Glass have no diffuse component and we may disable 'Use Simple Diffuse' and 'Use Indirect Illumination', because it really not needed.
Now we'll tune Specular... For glass recommended 'Blinn' or 'Wet' specular models. Select specular likely for you (don't forget to disable 'Phong' specular, it enabled by default).
For 'Blinn' model set:
- 'Eccentricity' = 0.05
- 'Specular Roll Off' = 3.0
For 'Wet' model just use it with default settings
If you really don't need specular for optimize rendering you may diable all specular and diffuse models, it will slightly increase rendering speed.
Render...

Simple Glass
We have black solid shadow now. For getting trasparency shadow we should use shadow shader.
You may just connect p_MegaTK 'Shadow Shader' slot.
Or if you need more control for shadow you may use p_shadow_transparency shader (or any other).

Simple Glass with shadow shader
Shadow shader compute not physicaly correct shadow. If you need physical correct shadow you should connect Photon shader, for example dielectric_material_photon and enable Caustics.

Simple Glass Men model with shadow shader
Create model like on image:
The model should be consist of 3 objects:

Glass Model
Check normals of you objects. Normal should be like on image:

Normal Direction on Glass Model
Create and assign p_MegaTK shader for 'yellow' object. Set followed attributes:
- 'Use Reflection' = On
- 'Coefficient Reflection' = 1
- 'Use Refraction' = On
- 'Coefficient Refraction' = 1
- 'IOR_In' = 1.5
- 'IOR_Out' = 1.0
- 'Absorption In' = 0.4 0.8 0.4
- 'Absorption Out' = 1.0 1.0 1.0
Create and assign p_MegaTK shader for 'red' object. Set followed attributes:
- 'Use Reflection' = On
- 'Coefficient Reflection' = 1
- 'Use Refraction' = On
- 'Coefficient Refraction' = 1
- 'IOR_In' = 1.333
- 'IOR_Out' = 1.0
- 'Absorption In' = 0.8 0.24 0.33
- 'Absorption Out' = 1.0 1.0 1.0
Create and assign p_MegaTK shader for 'blue' object. Set followed attributes:
- 'Use Reflection' = On
- 'Coefficient Reflection' = 1
- 'Use Refraction' = On
- 'Coefficient Refraction' = 1
- 'IOR_In' = 1.333
- 'IOR_Out' = 1.5
- 'Absorption In' = 0.8 0.24 0.33
- 'Absorption Out' = 0.4 0.8 0.4
Open Render Settings and set followed parameters in Raytracing tab:
- 'Reflection' = 4
- 'Refraction' = 5
- 'Max Trace Depth' = 8
- 'Shadow' = 3
Render...

Glass Render

Glass Render