Today we’ll be making a bacteria model as seen under an electron microscope. When you use an electron microscope, the object you watch is no longer alive, so the bacteria is not going to be animated. I’ll be using the 2.93 version of Blender.
So, let’s get started. Here are the steps for you to follow:
Table of Contents
Step 1 – Create a Basic Bacteria Model
Delete the default cube and save your file. Now we’re ready to model a single bacterium. Add a UV sphere, rename it ‘bacterium’ in the Outliner, go to edit mode, wireframe shading (hit Z and select wireframe), select all and rotate the sphere (R Y -90). Here’s what it looks like in front view:
Then deselect all and select just the right half of the sphere. Hit G X 8 to move the selected part along the X axis:
Next, hit Ctrl + R and hover your mouse cursor over the mesh. Hit 40 to add 40 cuts:
You can now switch back to solid shading (A). Go to object mode and in the Object menu (B) select Shade Smooth:
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Step 2 – Add Material to the Bacteria Model
Let’s add a material to the bacteria model. Go to the Shading workspace (A). Hit the New button in the Shader Editor to add a new material. A Principled BSDF material is added. To view the material, switch to Rendered shading (B):
We want the material to be black, so set the Base Color to black (A). Also, it shouldn’t be shiny, so turn Roughness all the way up to 1 (B):
Now, we want the bacterium to be shiny just on the edges, with the middle part remaining dark. To this end we’ll combine the Principled shader with another shader. Hit Shift + A and add an Emission shader (A). Then add a Mix shader (B). Make sure the Principled shader is plugged into the upper socket of the Mix shader and the Emission shader to the lower one:
You can now play with the Mix shader’s factor (or Fac). If you set its value to a number closer to 0, the Principled shader dominates over the Emission shader. If you set the value to a number closer to 1, the Emission shader will take over.
But we’re not going to control the factor manually. Instead we’ll add a Layer Weight node. You will find it under Input when you hit Shift + A. Then connect the Layer Weight’s Fresnel socket with the Mix shader’s factor:
Now you can play with the Blend value of the Layer Weight node. Set it to 0.2 (A) and you will see the emission shader take effect just on the edges of the model (B):
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Step 3 – Add Modifiers to the Bacteria Model
We now have the basic shape and material, but the bacterium looks too smooth. Let’s add some bumps to it so that it looks more natural. You can switch back to the Layout workspace (A) and select the Rendered shading (B).
First let’s add a subdivision surface modifier to the bacteria model. To do that go to the Modifiers tab (C) and click on the Add Modifier dropdown (D). Then select the Subdivision Surface modifier. Set Levels (both Viewport and Render) to 3 (E):
Next, add a Displace modifier. Hit the New button to add a texture:
Then go to the Texture tab (A) and set Type to Clouds (B):
The bacterium now looks odd, but don’t worry about that. All you have to do to fix this is go back to the Modifier tab and set Strength to a lower value like 0.1:
Now the bacterium looks better.
Step 4 – Make a Collection of Bacteria
The bacterium looks fine, but it will look even more realistic if we bend it slightly. In the final scene there are going to be lots of bacteria, so let’s first create a couple of them and then bend each one in a slightly different way.
Go to top view (Num 7) and make sure the bacterium is selected. Let’s say we want to make five different versions of the bacterium. To keep things organized, let’s create a special collection that will hold all our bacteria. To do that go to the Outliner and right-click somewhere on the first row that reads ‘Scene Collection’. Then select New Collection:
Rename the collection Bacteria and drag the bacterium object into the collection:
Now hit Shift + D to duplicate the bacterium and then immediately X to constrain the duplicate to the X axis. Move the new object to the left. Repeat this step until there are five bacteria altogether. You can also see them in the Bacteria collection you just created:
Next, will differentiate the sizes of the five bacteria. With the last object you added selected, hit S X .8 to make it slightly shorter.
Then select the one to the right and hit S X 1.1 to make it longer.
Then select the one in the middle and hit S X 1.8. This is going to be the longest bacterium. Hit G Y and move it slightly up so that it doesn’t overlap with the other cells.
Next, select the last but one bacterium. Hit S X .6. This is going to be the shortest one.
We’re not going to scale the original cell.
The lengths of the cells will change anyway when we add the Curve modifier, but that’s fine.
Now you should have the following five cells:
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Step 5 – Bend the Bacteria
Yes, sure, they are too straight. Let’s bend them now. To do that we can use a Curve modifier, but for the modifier to work we first need a curve. So, hit Shift + A and under Curve select Bezier. Then hit G and move the curve somewhere below the bacteria:
Hit S 30 to resize the curve. Move it down so that it’s below the cells:
We could now go to edit mode and modify the curve, but let’s keep it simple. It’s curved in a certain way and it will do. Now we’re going to add the Curve modifier to one of the objects and then copy it to the others. So, let’s select just the original bacterium and add the Curve modifier:
To see it better, I collapsed the other two modifiers by clicking on the down arrows to the left of their names. Anyway, now we must select the curve that our model is supposed to follow. Click on the Curve Object slot (A) and select the Bezier curve we just added (B):
Now watch what happened to the bacterium:
Now hit G and try moving the bacterium around. You will see it change according to how the curve behaves in different places.
Now select all the bacteria one by one by holding down the Shift button and left-clicking them one by one. Make sure the original bacterium is selected last. This way it becomes the active object, which you can tell by its color:
Now click on the arrow (A) in the Curve modifier to expand the dropdown and select Copy to Selected (B):
This way the modifier will be copied to all the cells:
Now select each bacterium one by one and move them around until they look the way you like, for example something like this:
Now select each bacterium one by one and apply the Curve modifier by selecting the Apply option:
When done, we don’t need the curve anymore, so select it and hit X to delete:
There’s one more thing to do. Right-click on the Bacteria collection in the Outliner and hit Select Objects. This will select all the bacteria. As you can see, the origins of the objects are outside the objects. These are the little orange dots:
Go to the Object menu and under Set Origin select Origin to Geometry:
Now everything is ordered:
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Step 6 – Create a Particle System
We want way more bacteria than the five we have. Let’s create a particle system. To do that we need an emitter, so let’s create a plane. Still in top view, hit Shift + A and under Mesh select Plane. Make sure the plane is in the main collection, not in the Bacteria collection:
Then hit S 50 to scale the plane:
Next, with the plane still selected, go to the Particle tab (A) and hit the little plus button (B) to add a new particle system:
Select Hair (A) and then orbit the scene so that you can see the particles (B):
Set the number of particles to 100 (A). Then, under Render, set Render As to Collection (B) and under Collection select the Bacteria collection (C):
Now you can see 100 bacteria. But they are pretty small. Set Scale to 0.3:
At this point each of the five bacteria versions is used exactly the same number of times. But we don’t want there to be so many big bacteria. If you now select the long bacterium in the 3D Viewport, you will see that it’s bacterium.002:
To change this, select the plane again and check the Use Count checkbox (A). Hit the arrow (B) to expand and select all the bacteria one by one (C), except bacterium.002, and set the Count value for each of them to 3 (D):
Now select all the bacteria in the Bacteria collection and move them away from the plane by hitting G X and dragging them to the right:
Now we’re going to rotate the bacteria so that they are more or less parallel to the plane. Under Collection check the Object Rotation checkbox. This will make the particles rotate along with the original objects. Now hit R Y 90 to rotate the selected five original objects:
But we don’t want the bacteria to be fully parallel to the plane. Let’s randomize their rotations. Select the Advanced checkbox (A), then the Rotation checkbox (B) and click on the arrow to expand. Set Orientation Axis to Normal (C) and Randomize to 1 (D):
Step 7 – Align the Camera
Now we are ready to align the camera. Orbit the scene until you see what you’d like to see in the final render. Let’s say this looks OK:
Now go to the View menu and under Align View select Align Active Camera to View:
Here’s what the camera can see (the portion of the image in the rectangle in the middle):
Select the camera in the Outliner (A) and go to the Object Data tab (B). Set Focal Length to 25 mm (C):
If we now rendered an image, we would see the plane, which isn’t what we want. So, select the plane and in the Particle tab under Render uncheck the Show Emitter checkbox:
One last thing. Go to the World tab (A) and click on the Color slot (B). Then drag the slider on the right all way down to black:
Step 8 – Render the Image of the Bacteria Model
We are now ready to render the image. Before we do, though, don’t forget to save your file. Then go to the Render menu and select Render Image:
After a while you will see our final image in the Image editor that in most cases will open as a separate window:
If you want to save the image on your disk, which is by all means worth doing, just go to the Image menu in the Image editor and select Save As… Then find a location (A), give your file a name like Bacteria.png (B) and hit the Save As Image button (C):
That’s it. Our bacteria model is finished. I hope you liked the tutorial. Feel free to leave your remarks or questions in the comments down below.