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How should the Parallax node be used?

08 February 2016 19:06
I'm following the documentation about parallax maps, but I'm not sure if I'm doing it right. Seems like I'm just getting the bump, but not parallax.

If all the settings are defined in the Texture Context, what is the node for? Am I missing something?



My .blend file

I'm just hoping to understand this better. Thanks.
09 February 2016 10:36

If all the settings are defined in the Texture Context, what is the node for? Am I missing something?
Yes, it's must be done in another way. I prepear for you an example using your texture. Some explanation: Hight map from Alpha chanel must be connected to Height Map Input in Parallax node, to the Input UV must be connected Output UV from geometry node, and then Output UV of Parralax node must be connected to the Input UV of Normal Map texture and then connected to the Material Normal Input. That the simple scheme.
Heres your Example
Blend4web and that kind of thing.
09 February 2016 18:38
Great! Thank you, Mikhail!

There is just one point I would like clarification on.
The documentation says: "A height map should be present in the alpha channel of a normal map."
I thought this meant I should include the height map as the A channel of an RGBA .png file.
But looking at your node setup, the alpha channel is not being used. Instead the Value (RGB to grayscale) output is being used.
This must mean the true height data is being ignored. (But in Blender Internal the Texture nodes don't have Alpha output - so I don't see a way to isolate the alpha channel.)


I thought that maybe my understanding was wrong, and I should use two separate images:

Normal Map
- and -
Height Map

But when I tried this it broke the parallax effect. What did I do wrong?
09 February 2016 19:15

I thought this meant I should include the height map as the A channel of an RGBA .png file.
But looking at your node setup, the alpha channel is not being used. Instead the Value (RGB to grayscale) output is being used.
This must mean the true height data is being ignored. (But in Blender Internal the Texture nodes don't have Alpha output - so I don't see a way to isolate the alpha channel.)
"Value" of Texture node in node material is Aplna chanel, so it's not just a conversation of image from RGB to BW. What you read in documentation is related to setup of parralax using standart blender material (without using node system), otherwise you need to look in the Special Nodes section of documentation.

I thought that maybe my understanding was wrong, and I should use two separate images:

Normal Map
- and -
Height Map
In node system you can use separated Hieght Map, but put your height map to Alpha Channel of Normal Map texture is much more optimize and economy in recources.
Blend4web and that kind of thing.
09 February 2016 19:53
OK, I got it now!
I had a fundamental misunderstanding about the Value output.
I always thought "Value" or "Fac" outputs were just grayscale data, and only outputs labeled "Alpha" were alpha.
Today I learned…

What you read in documentation is related to setup of parralax using standart blender material (without using node system)
I see how this works now, and I noticed how if the node system is used, the settings in the node setup override the settings in the Texture Context (for Scale, Steps, and Lod distance).

I'm so happy to know how to use parallax now!
Once again, thank you!
10 February 2016 10:14

I'm so happy to know how to use parallax now!
Once again, thank you!
I'm glad I could help.
Blend4web and that kind of thing.
05 April 2017 15:22
Hello

Why You use Alpha for Height map?
By default Height on Blue chanel.
isn't it?
05 April 2017 16:24
Why You use Alpha for Height map?
By default Height on Blue chanel.
isn't it?
Blue channel it's not a height. RGB channels usen as XYZ directions of the vectors to direct normals on the mesh. So it's not a height and usuialy it's alwayes baked in the normal map is barely visible with less value of information that needed for parralax node.
Blend4web and that kind of thing.
05 April 2017 19:23
Yes, indeed.

Thanx 4 explain
 
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