Checker1 will go on the left, because it is outputting outAlpha. DisplacementShader1 will go on the right, because it is receiving outAlpha into displacement. Select checker1 and click the Reload Left button. Now select displacementShader1 and click Reload Right
Now is the easy part. Click first on Out Alpha, then click on Displacement. If you look back in your Hypergraph you'll note that there is a connection line drawn between them. The checker is now connected to the displacement, but the displacement isn't connected to the actual shader. To do this, select displacementShader1 and Reload Left. Select lambert2SG (the shading group) and Reload Right. Once both are loaded, click first on Displacement, then on Displacement Shader. This will technically connect displacementShader1.displacement into lambert2SG.displacementShader.
Now if you render, you should get an image like the example at the beginning of this section.
Ok! Woohoo! We have a cool checkered plane thing with holes and stuff. Wow! Well, what if I want the white higher? How can I change that? Short answer, you can't. Long answer, you can. Since the outAlpha is mapped directly into the displacement shader, we can't control or change the amount or intensity of the map without making the white a bit darker or brighter. What if this was a detailed displacement map for a face? You don't want to go through your map and keep adjusting the levels and contrast in Photoshop, then go back into Maya, render, then go back into Photoshop, adjust, etc.
So what we will do is create a multiplyDivide node. What it does is take in any inputs and multiply, divide or power it by a value you set, then send the result as the output .
checker1.outAlpha into multiplyDivide.input1X multiplyDivide.ouputX into displacementShader1.displacement.
Let's create the multiplyDivide node.
Back in the Connection Editor, select first checker1 and press Reload Left, then select multiplyDivide1 and Reload Right. Connect "Out Alpha" into "Input1 X"
Select multiplyDivide1 and Reload Left, then select displacementShader1 and Reload Right. Connect "Output X" to Displacement
If you render now, you should see exactly the same thing as before. We need to change the value that the outAlpha is being multiplied/divided by. Select multiplyDivide1 and go to the Attribute Editor. Notice that the first box of Input1 is yellow. That means it has an incoming connection. The first box of Input2 is where we change the intensity of the displacement. If I change it to 10 instead of 1, there will be 10 times as much displacement. If I change it to .5, there will be half as much displacement. Go ahead and try it
Pretty cool, huh? Try doing the same thing only using images you've made. Here is a quick examples using an image made in Photoshop. Instant mountains, no modeling