View Full Version : define normal

05-07-2015, 08:21 AM
I downloaded the Pixar textures they gave away for free. There are 3 files.

Blue_glazed_pxr128_bmp.tif - apply this to the bump channel
Blue_glazed_pxr128.tif - the base texture, apply this to the color channel

Blue_glazed_pxr128_normal.tif what is this, I think I apply it to the specular channel

thanks for any help

05-07-2015, 08:40 AM
In Node Editor you have Normal input.


05-07-2015, 09:10 AM
thanks but what exactly does the normal do to the texture

05-07-2015, 09:13 AM
thanks but what exactly does the normal do to the texture

Normal map is replacing existing surface normal vector.

Bump map is perturbing existing surface normal vector, depending on Bump Amount.

05-07-2015, 10:34 AM
A "normal" is the direction a polygon is facing. If you have a single polygon on the X-Z plane, it's normal is pointing up the Y axis.

Bump maps and normal maps are a way to fake more geometry than what's actually there. By having a bump map or normal map, the rendering engine can put in shadows, phong / specular highlighting, adjust diffuse, etc. as if there are a lot more polygons and surface variation than there actually are.

Both are fake geometry, though. If you get close enough, especially from the side, there are no real bumps so it'll look flat (unless you use a bump displacement with a subdivided polygon).


05-07-2015, 08:29 PM
You can use the normal map if you are going to use these Pixar textures on flat surfaces. On curved surfaces it will give incorrect results. The bump map will work properly on curved or flat surfaces.


05-08-2015, 04:53 AM
thank you all very much

05-08-2015, 06:45 AM
Here's an article for you to look at over at digital tutors http://blog.digitaltutors.com/bump-normal-and-displacement-maps/