Electron Microscope

The use of view dependent falloff (incidence) is indeed one of the main characteristics of electron microscope images. However, there’s a whole lot more to it.

Creating electron microscope material
f you don’t have a virtual spore (or alike) of your own, open the scene spore.scn from the CD. Select the spore object, apply a Lambert shader and set both the Diffuse and Ambient colors to almost pure white. Switch to the Indirect Illumination tab and set the Incandescence Intensity to about 0.75 before pressing [7] to open the Render Tree. From the Nodes>Texture Generators menu get a Gradient Node and connect it to the Incandescence input of the Lambert node. Open the Gradient PPG and press the White/Black preset to limit the gradient to shades of grey. Switch to the Input tab and change the Input Type to Scalar input set the Active Maximum Range to 2. By controlling the gradient with an incidence node you can really fin-tune the shading, so from the Nodes>Illumination pick Incidence and connect it to the input of the Gradient. Open the Incidence PPG and set the Bias to about 0.7 and the Gain to 0.65.

While you’re starting to get some interesting result in terms of the shading, the scene still appears rather evenly illuminated and lack the feeling of depth. To fake the appearance of light bouncing (and being blocked by additional spores) you can make use of the Ambient Occlusion shader. From the Nodes>Illumination menu get an Ambient Occlusion node and from the Nodes>Mixers menu get a Mix 2 Colors. Now plug in the Lambert node to both the base_color and the color1 input of the Mix 2 Color node and plug the Mix 2 Color node to the Surface input of the Material node. Open the Mix 2 Color PPG and change the Mix Layer Mode to Hide/Reveal(Multiply). Multiplying the material with itself instead of using a solid color will help you bring out some of the fine details and without losing the effect of the incidence. Open the Ambient Occlusion PPG and increase the Spread to 0.75 or so and connect the node to the weight input of the Mix 2 Color.

The last step, which will really bring out the shading of the spores, is to add a bump and/or displacement map. Create your own or feel free use the one on the CD.

The project files used in this tutorial can be found at:http://www.Redi-Vivus.com/Caffeineabuse/Electron_Microscope.zip

As each of the nodes used in the render tree has a noticeable effect on the final image, please take the time to experiment with their respective settings.