After knowing how each channel is rendered now we can make the following analogy:
-i will assign a lambert to the high poly (cylinder and plane), set the color to neutral gray (128 128 128),set the incandescence to neutral gray also (128 128 128) and also set the diffuse to 1
-we look at the cylinder from top (orthographic view) in viewport
- create a normal directional light with color full white and intensity 1 coming from right ( the light will be parallel with the screen)
-create a "sucker" directional light ,i do not know if you are familiar with the term :) "light suckers" ... i have seen them named like that on some forums and i will name them the same ... it will be a light with a negative intensity ... so when rendering the "sucker" light actually will subtract ,"suck" light thus darkening the scene ... pretty handy when you have overbright areas in the scene and if you adjust the attributes for the lights already in the scene you will mess the lighting in other areas ... this way you can add a sucker light and fix the problem, ... so add a sucker light with color full white and intensity -1 coming from left also parallel with the screen ( so both lights will be in tangent-binormal plane )
If we compare the screenshot form maya viewport and the red channel in the computed normal map they will look exactly the same.
Same applies for the green channel if you test, this time the same normal light will come from top and the sucker light from below ( also same lights in tangent- binormal plane ).
For the blue channel you will keep only the normal light but this time lighting from straight top ( light parallel with nomral vector in TS )
If i want to see all the channels together i will have to change the color for each light to affect only one channel
So for the setup below i will have 5 lights
With the lighting setup from above you can check realtime the normal map from the orthographic top view for any geometry
Now this info won't be too useful since you still have to handle geometry ... but check the next paragraph ... you can simulate this lighting setup within photoshop with layer styles and all you have to do is make selections :).
4.4.2 Normal maps in photoshop:
Now i will try to simulate in photoshop the same effect as shown above with lights within maya but this time using layer styles.
I will set the background color to 128 128 255
I will need 5 layers, one for each light ( made 5 layers and changed their fill opacity to 0 then i will make selections and fill them within each layer but only the effects will be visible)
for Red normal light apply an effect like below (bevel and emboss), uncheck use global lighting ,set the angle to 0 (the light will come from right),set altitude to 0 (light parallel with the screen) ,highlight mode set to overlay with color 255 128 128 (RGB) to lighten only the red channel and opacity to 100% , set opacity for shadows to 0 (don't need that)
you can play however you want with the settings under structure but you have to make sure that all the effects have same settings
