Source: Blendamator.com, 2023
With the creation of our character now complete, it was time to learn a new method to texturise a 3D model; normal mapping.
Not every minute detail of a 3D model needs to be sculpted, but instead the illusion of surface detail such as lumps, bumps, wrinkles and textures can be created while maintaining the existing sculpted detail using normal mapping, which enhances the realism of the object or character without increasing its geometric complexity (adobe.com, n.d.).
Normal mapping produces the effect that ‘real’ geometry has been created, through only the addition of texture. The ‘normal’ in normal mapping refers to a vector or line perpendicular to a surface, and as can be seen below, in basic terms, the computer programme uses the angle between a polygon’s surface normal, and the direction of the light source to determine how the light reflects, and the degree of lightness or darkness of each surface polygon (Treehouse blog, 2015).
Source: Treehouse blog, 2015
However, a downside to using normal mapping is that the overall sculpt of the model must be complete before textures are applied, as normal mapping can’t handle further surface detail changes.
The class workshop was to then add additional detail to the 3D model of the elephant’s head provided below, and to create texture using the normal mapping process.
Remembering to avoid using ‘dynamic topology,’ or ‘remesh’ which had created numerous n-gon issues in my initial bull’s head sculpt, after shading smooth and adding a ‘multiresolution/multires’ modifier, which not only gives me the ability to subdivide my mesh in a similar way to the ‘subdivision surface’ modifier, but also when using ‘sculpt’ mode, allows me to edit the new subdivided geometry without applying it; I was ready to begin.
Comparing the two images, my sculpting has created a more authentic head shape, and added definition to around the eyes, and what in human terms would be classed as the bridge of the nose. The ears, which now also feature inset ear canals, have also been reshaped and defined. Wrinkling too has been added at various points along the length of the trunk, as well as to the top of the head, and to create an outcome with personality and a more cartoony style, I’ve added an exaggerated furrowed brow, apple cheeks and saggy jowls.
Happy with my final sculpt, I could now apply texture to the skin. To create my normal map, using the ‘shader editor’ I first created a blank image, before adding a png file of the image texture, increasing the resolution to 2048 X 2048, and changing the colour space to ‘raw,’ before finally ensuring the normal map will use the image as its base colour, by connecting ‘colour’ to ‘colour.
Next, after changing the render engine to ‘cycles,’ following almost the same process learned during the early weeks of the module, I baked my normal map using ‘multires’ and bake type: normal to create an .fbx file for use in Substance 3D Painter, while also remembering to change the render engine back to ‘eevee’ before exporting the file. I then added texture to the model in Substance 3D Painter, by applying the normal map in the texture settings.
Finally, once textures had been applied to the model, I exported my texture files back into Blender, and after plugging the relevant texture map to the applicable area, here’s my completed model.
All in all I’m satisfied with the result, and now I’m aware of how the illusion of realistic surface details such as wrinkling can be created with normal maps, that neither increase the polygon count, or affect topology, perhaps a 3D model of my original concept of an old, frail and decrepit bull might be on the cards at some point in the future!
References:
adobe.com. (n.d.). What is Normal Mapping? – Adobe. [online]. [Accessed 19 December 2023].
Available at: https://www.adobe.com/products/substance3d/discover/normal-mapping.html
Blendamator.com (2023). How to Utilise Normal Maps in Blender – Davy. [online]. [Accessed 19 December 2023].
Available at: https://blendamator.com/normal-maps-blender/
Treehouse Blog. (2015). Understanding Normal Maps. [online]. [Accessed 19 December 2023].
Available at: https://blog.teamtreehouse.com/understanding-normal-maps