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Game Editing => Video Channel => Topic started by: kat on February 18, 2014, 04:19:20 PM

Title: Making a normal map from an image (screencast)
Post by: kat on February 18, 2014, 04:19:20 PM

(https://www.katsbits.com/images/tutorials/normal-maps/screen_make-normal-maps_med.jpg)
Screencast (audio but no instruction) whilst making a normal map from a pre-existing diffuse texture - in this instance a bitmap image from Return to Castle Wolfenstein. Software used - Corel Photo-Paint (X5) (image-editor) to build the 2D grey-scale template for conversion, nJob for converting the grey-scale image to a normal map, and Blender for testing the result.

Process
Open the original texture in your image-editor of choice and assess how the grey-scale template should be constructed, then block out the main forms using a range of appropriate shapes. In essence BLACK tones recede backwards from the mid-tone average, WHITE protrudes up or out. This means any design elements that appear to be raised 'above' others should be lighter tones, whereas elements that sit behind or under, darker tones.

Special note for rivets and other forms
Depending on the type, dome-topped rivets can be formed by adding a slight blur value to the outer edges as this results in a 'sloped' or gradual falloff during conversion to a normal map. Positioning such objects over a slightly darker and wider objects create the indentations and recesses typical of the holes in which the rivets sit.

Additional Resources
Title: Re: [screencast] making normal maps from images
Post by: ratty redemption on February 19, 2014, 04:08:38 PM
cool, very nice textures and interesting workflow. are you going to record a video for creating spec maps?

that coral photo paint looks similar to the old paint shop pro versions i used to work with, but sadly no longer have access to the install disks.

the last image editor i used for textures was the free paint.net, which had some cool filters but very limited brush tools, so as i'm going to working with bitmaps again in the very near future, i think i might give gimp one last try, and if i still dislike the interface, then i'll probably buy the latest paint shop pro.
Title: Re: [screencast] making normal maps from images
Post by: kat on February 19, 2014, 05:02:05 PM
Might be doing one for the next screencast, just choosing a texture at the moment. Having said that though, specular maps are generally just darkened versions of the grey-scale template (not the texture itself mind you) because that already contain the type of height data that might lend itself to 'highlights' normally attributed to height/depth expectations - rivets and outer exposed edges and so on. Should more specular details be needed it generally just means adding to the template with a mind to where highlights would appear.

Corel own PaintShop Pro (have for a good few years now) so there's likely some crossover between the two. But.. the basic principle is agnostic, so long as the dark/recess and light/protrusion is followed.

For clarification, the texture/s is/are from Return to Castle Wolfenstein.
Title: Re: [screencast] making normal maps from images
Post by: ratty redemption on February 19, 2014, 05:06:13 PM
understood, cool.