Learn to create Normal Map with FREE NVIDIA plugin and shave off rendering time.
When you want to add fine detail to meshes, you can either use real geometry or normal-maps. There is also the option of bump maps, but these are mostly obsolete nowadays. Where bump maps add the illusion of height to details, normal-maps go much beyond that.
Normal-maps look more realistic than bump because they carry the complete 3 dimensional data, and not just height alone. This tricks the ray trace rendering into believing it’s a real geometry and casts shadows accordingly. Quite simply, you can view from different directions and move lights, and you’ll get realistic 3d details.
Normal-maps are usually purple, with cyan and pink hues. The color change tells the renderer the angles of the normals of the surface. In case you’re wondering, ‘normal’ is the technical name given to the direction which is perpendicular to the surface. So wherever the normal changes, the color changes; while the flat surface is purple.
If you already have bump maps, you can use them to create a normal map using the free Nvidia plugin for Photoshop. Download and install it. After installation you’ll find it as a Filter > Nvidia Tools > NormalMapFilter.
Just open up your Bump map in Photoshop and apply this filter. You don’t need to worry about all the settings to create a simple normal map. Just follow my steps:
- Create 3 duplicates of your bump map.
- For each duplicate layer, apply the NormalMapFilter with a filter type of 3×3, 7×7 and 9×9 respectively.
- Now, by using the opacity setting for layers, blend all of these 3 maps.
- We now have a composite normal map with sharp and smooth fading detail.
- Now plug this map into a VRayNormalMap and into your material bump slot.
- You can change the amount for altering the strength of the effect and get more definition.
I still prefer to use VRayDisplacementMod – since it gives me more defined lines in exchange for a longer rendering time.