How do I know what values are being outputted from a given node?

[mr.michaelrader]

I'm having trouble wrapping my head around the shader network because I don't know what's going on behind the scenes. When I use the utility node and set the color mode to Object ID, how do I know what exactly is being outputted? And same for rgb_to_float, how do I find out what value it is outputting so I know how to use it properly? Or am I just thinking about this all wrong?

[Stephen.Blair · Accepted solution]

Object ID gives you a color value based on a numeric ID assigned to an Arnold shape node.

The output color from rgb_to_float is determined by the mode (min, max, average, and so on).

min is the minimum of the R, G, and B values

[mr.michaelrader]

I believe you, but how do you know this? Where can I find deeper information like this? Their manual hasn't proven very useful. And I'm sorry, but still don't understand the rgb_to_float. This sounds like it is taking in three values (R, G and B) and spitting out a floating number (2.35, 1.2 etc.) How do I know or see that number? Is there some console that shows the passing values?

[Stephen.Blair]

RGB is three values.

If mode is max, then rgb_to_float takes the largest value of the three, and outputs that as a float.

You cannot see the exact output in a console. Logging values for every shading point would be very expensive.

You can visualize the output like this:

[mr.michaelrader]

Thank you, however, I do disagree it would be expensive. A simple number representing a nodes current value at the bottom of the node would do a lot for understanding how values are moved and changed around. I hate guessing or assuming what is happening to the traveling values, or having to plug into beauty each step to ensure I'm getting what I need.