Bump and normal map info

Bump and normal map info

I am looking for info on the bump maps and normal maps. Have done no searching yet but the C3D help and found only this although it's late and I have just started to search. This confused me:
Bump map
A material defines how an object will look when rendered. The material defines its colour and how it reflects light, but you can also simulate subtle bumps and textures in the surface of an object by specifying a bump map, which is a monochrome image where the darker the parts of the image, the higher the supposed bump on the object. Bump maps affect reflections, light refractions and other parts of the renderer, and when used properly can help produce very realistic images.
I thought white raised the bump and black lowered it. I guess according to this I am wrong. Can someone tell me if the help statement is correct black is higher?
I found this very interesting: https://www.cheetah3d.com/forum/showthread.php?t=5778

You´re right about high&low values. The Z-buffer works other way around.
The GIF pretty much explains it - I guess.

Left is Cheetah3d rendered normal map texture, right a vector based 16bit exr image.

The advantage over a normal map is the bump map texture can be painted, 16/32bit lossless PNG and is "human-readable" - while the normal map is software generated (Krita foundation will tell a different story - but I for myself don´t get the normal map brush-"engine" to run properly) and normally just 8bit JPEG.
I´m still unsure what you´re asking for. Is it normal map texture generating inside Cheetah3d or the missing normal map export to FBX?

Cheers
Frank

From what I remember about Poser they have a node editor too.
So in case one software does interpret a given bump map "upside down" compared to another app, you need to put a node in between that inverts the signal.
In Cheetah you can use the "subtract" node with value 1 for A and the node input into B. Or use the gradient node and exchange black and white markers.
In Poser there should be similar ways.

I´m still unsure what you´re asking for. Is it normal map texture generating inside Cheetah3d or the missing normal map export to FBX?

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I am looking for enlightenment about bump and normal maps. Thank you for the Bump(paint upon tip). Also Black does raise white lowers correct?
Other questions what hight to raise the bump as compared to normal.
It seems the normal is the same at 1 as it is at 10.And that Is that correct.
Which normal map to use?

uncle808us said:

I am looking for enlightenment about bump and normal maps. Thank you for the Bump(paint upon tip). Also Black does raise white lowers correct?

Click to expand...

No the opposite is correct as you first guessed:

Cheers
Frank

Thanks Frank.

It's in every app like this: black down, white up, 50 % grey neutral. If it wasn't like this in Cheetah, you couldn't use any bump map from somewhere else (like pbrs).

The manual should be changed.

Rita 4 Normal map filter.

Heads up.
I just found out that the new update of Krita(4) has a normal filter hight map to normal map. So you can save a copy of the hight map to edit and also have your normal map.
Now if I can figure out which of the two choices of normal map to use in C3D (open gL or direct X).

You need OpenGl. DirectX is for Windows.
So you have it working? I struggled with the set-up a few times and gave up for the time being. Mind sharing a working file - just empty with the layers?
I was here already: https://docs.krita.org/en/reference_manual/filters/map.html?highlight=normal
but maybe too impatient. :redface:

Cheers
Frank

frank beckmann said:

You need OpenGl. DirectX is for Windows.
So you have it working? I struggled with the set-up a few times and gave up for the time being. Mind sharing a working file - just empty with the layers?
I was here already: https://docs.krita.org/en/reference_manual/filters/map.html?highlight=normal
but maybe too impatient. :redface:

Cheers
Frank

Click to expand...

Check your email I sent you a Krita file.

The only thing that stops me with Krita is the Pen lag. So I'm still using ClipStudioPaint. except I'll now use Krita for normal maps. The reason I use normal maps is that a client can not mess them up like a hight map.

How cool is that - thank you Sir!
Have a nice one.

Cheers
Frank

Bump maps are the earlier technology. It simulates additional detail at render time by causing the render to "fake" that surface detail raises up or pokes into that surface, but only in a straight line in or out (i.e. along the perpendicular). The renderer gives you a highlight and a shadow from a bump or pit that doesn't actually exist.

Normal maps use three way shading with the color channels to again cause the renderer to "fake" that surface detail is present. This time however, the fake detail can have the appearance of bumpiness in any 3 dimensional direction (within reason). Color ranges along a red/cyan gradient cause the detail to fall on the X direction, green/yellow gradients cause detail to appear in the y direction, and blue/yellow along the z direction.


https://en.wikipedia.org/wiki/Normal_mapping


This fake detail, with it's crazy color schemes is nearly impossible for people to actually paint by hand. A bump map by hand, yes, a normal map, not likely. Instead, high polygon meshes, typically from a sculpting program or a 3d scanned object, are baked out to render the detail present as a normal map. That normal map can be applied to a much lower detail mesh, that will have the appearance of the high res mesh, but render much faster. Faster rendering is always useful, especially for games.


Interesting that Krita can calculate a normal map, I'll have to look into that. Thanks for posting.

Thanks for the link to wiki.

Interesting that Krita can calculate a normal map, I'll have to look into that. Thanks for posting

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