*@Pierpaolo Andraghetti* The values only show up, when you click on the image. The mouse button depends on what you use for selection. With leftclick-select you use the right mouse button and vice versa

*@Victor Bonar Panggabean* I'm not entirely sure, I understand what you mean. On its own, negative RGB values don't affect the other color channels.

If you mean the effect, that negative color values for the base color of the Principled BSDF shader affect the color, that you see, that is exclusively due to the specular part of the shader. The negative components effectively subtract from the reflection, changing its color.

That works in the same way as you can have negative emission as absorption with lamps or emission shaders.

*@Simon Thommes* Hi Simon, sorry for my english. I mean in the blendfile that you provide for us. In the vectors scene, if i move the empty (target) to the +z direction then the arrow turns blue. But when i move the empty to the -z direction why is the arrow turns green? Just curious

*@Victor Bonar Panggabean* Ah, I see. Thanks for pointing this out!

The reason for this effect is the same I described in my earlier comment, I did not think of it when creating the file. I updated the file. Now the behavior is accurate.

*@Simon Thommes* Thank you Simon, will try explore the file again. Anyway i think you're the only instructor in this blender cloud who replies.. Haha.. Thanks alot

*@Victor Bonar Panggabean* That hasn't been my experience. To name one example, Julien K. responded to a question I had recently within a day or so. And my only other attempt at asking a question was also answered. Sounds like you haven't been as lucky. Still, painting everyone with one brush may not be so fair.

*@Victor Bonar Panggabean* I think the problem you are experiencing might be on the courses that are old training DVDs that are not uploaded by the instructors themselves, but as an archive by one of our maintainers. So those instructors don't see your comments unfortunately.

But on the courses by those of us working at the Blender Studio currently we all respond regularly as far as I know. I know that, as an example, Julien Kaspar replies to all comments in short time.

*@Simon Thommes* Yes you're right. Ah, so the old training courses was not uploaded by the instructors themselves.

Wow, that's awesome so now there's a new division developing the blender training material?

Anyway, if i can make a suggestion, it will be much helpful for the students that don't speak english well (like me) if there is a feature that can upload picture in this Q & A section. So instead explaining what is happening in my screen, i can just screenshot and send it here so the instructor will easily understand the problem and therefore will be able to help the students easily.

*@victor p* Yes, as far as I know that feature will be supported in the future. Right now you can also do it, but you have to first upload the image and then link to it in the comment.

*@Simon Thommes* aha..yes you are right.

*@srkmail* That is exactly the shortcut that should work, which I am using as well. Are you sure that the addon is enabled correctly? You should save your preferences after enabling so Blender remembers your settings.

Do you see the Node Wrangler settings in the right property tab of your shader editor window? (shows up when pressing 'N')

*@Simon Thommes* Thanks a lot Simon. It is working after restart. Thanks for this wonderful tutorial.

@Jean-Christophe Sekinger Is this still happening to you? I cannot reproduce this error.

@Hendra Yahya Values and vectors are the base of all information that is passed in a nodetree and you can use them generally everywhere to inform your shader. This course goes more into depth of the node-based shading system in Blender, so having this base is important to build up on. The Principled BSDF shader specifically is topic of chapter 3.

@Theeverflare An average in general gives you a comparable measure for a property of a group regardless of the size of that group. It is just calculated by the sum of all the properties divided by their count.

If in the measure you are looking for different elements of the group have a difference importance, you have to weigh the average in the calculation with the weights of those elements.

In the example of the RGB Color one weighted average that you can look at is the luminance which give you information over how bright a color appears. If you just were to calculate the general average with (R+G+B)/3 that would be inaccurate in terms of luminance, as a pure blue for example is much darker than a pure green.

Because of this you have to weigh the different components of red, green and blue in a way that they are more accurately represented in the average. These weights are basically a measure of how much each color component is worth in terms of luminance. The weighted average then calculates as (R*wR+G*wG+B*wB)/(wR+wG+wB) where wR, wG, wB are the weights of the components. In the case of equal weighting this is exactly the formular from above: (R*1+G*1+B*1)/(1+1+1)=(R+G+B)/3

I hope that helps understanding this :)

@Simon Thommes Thanks i understand now

@Simon Thommes This class already started very well! For info our eyes percieves the luminance of a color differently depending of the channel: 0.21R + 0.72G + 0.07B

@Andreas Hoffmann You're right, both of these settings give you the linear values without additional color transformation. The main differnece between changing the Display Device and the View Transform is what is affected. You can see that for example the solid viewport is not affected by the View Transform but by the Display Device.