SpeedTree, Part 2 – Making Normal maps from Photos

We did an overview of SpeedTree last week, I wanted to show you what I was able to do from that point to create my own trees/plants. Using my own Leaf scans. First off, I wanted to run some tests in applications for generating Normals maps using my color map image.  There are a bunch of ways to create normals now from images.  I used the color map of a leaf from a SpeedTree  plant so I could have it’s Normal map to compare from the versions I got in other applications. I started with this Leaf from a topiary vines tree I purchased called Kudzu.

SpeedTree Color Map:

KudzuLeaves

SpeedTree Normal Map:

KudzuLeaves_Normal

Newer version of Photoshop has ability to generate a Normal map from Filters–3d–Create Normal Map.

photoshop_filter_3d_normal

There a few parameters that you can tweak in this popup.

photoshop_generate_normal

Here is the Normal map I got out of Photoshop

KudzuLeaves_Normal_photoshop

It’s not bad. I’ve found another application called “CrazyBump”. It’s a free beta software for Mac and PCs. It’s pretty good and straight forward to  use. You can also output displacements, specular, occlusion, and diffuse passes.

crazybump_app

You select “Open photograph from file”.

crazybump_shape

CrazyBump gives you more parameters to dial in  your normal map.

crazybump_normal_parameters

Here’s the CrazyBump Normal

KudzuLeaves_NRM_crazybump

Last Application you can also use is by Quixel called NDO. It is only available for PCs and is not free. It has a lot of editing modes and parameters to use as well. I’m not versed in it yet but there are things that I like within it. NDO and rest of Quixel suite works within Photoshop as a plugin. You have full control of creating your normals here. There is also modes for creating and exporting other maps like CrazyBump does.

ndondo_other_maps_exports

NDO Normal Map

KudzuLeaves_NRM_NDO

I’ll hook up these maps in Maya and you can see the differences (if any). Here are the results compared to SpeedTree. Some small variation between them all. They all work, but if I’d have to pick CrazyBump is the closest to match the SpeedTree normal. Plus, CrazyBump is free and it has more settings than Photoshop. NDO is a good choice but since it’s not free and it has a lot more bells and whistles for simple normals it might be overkill. Click below to see full size.

Image converted using ifftoany

This technique for creating Normals from images isn’t just for SpeedTree. This is great for texturing in general.  You can pull out additional details from your color maps into your new normal map without having to add too much additional geometry to your object. Here’s a simple card with a texture I put on it quickly.

geo_texture

Now see a render with just the color map and then with the normal created from the color map.

card_render

Even though it’s not perfect and I only spent like a minute on this it give the impression of more depth to the geometry of the card.

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