How can I make sharp geometric 3d models look more realistic?

Question

I'm making a scene in Blender with manufactured mechanical and electrical objects - cylinders, metal objects and so forth. I want to make these look real, be fully present with a sense of mass and substance.

3DCG has a tendency to make everything very sharply geometric, often looking mathematical and artificial. In other scenes, some organic curves, normal maps or particle systems would help make object look real. Like for example, making a simple plastic dog model look more believable, one can add more vertices for better definition, add texture layer, add fur etc.

My scene shows clean resistors, wires, metal strips and such, all sharply geometric. It's tricky to find ways to make the result less mathematical and more substantial, realistic and interesting to the eye.

What are some effective ways to add realism to these objects?

Answer 1

For one, you can bevel your objects.

Forgetting to bevel or chamfer edges is one of the most common errors committed by beginning 3D artists. There are almost no razor sharp edges in nature, and even most man-made objects have a slight roundness where two opposing surfaces meet. Beveling helps bring out detail, and really sells the realism of your model by allowing edges to properly catch highlights from your lighting solution.

In object mode you can bevel an object by using the Bevel modifier and in edit mode you can bevel edges and faces with Ctrl+B and vertices with Ctrl+Shift+B. The latter will allow you to interactively adjust the amount of segments with the mouse wheel.

Using the modifier.

Take a sharp object you just made, say a simple step. It's plain, simple and ugly when you look at it and would look out of place in almost any scene aiming for realism.

Once beveled, the edges are softened and it just looks more appealing as this is what we are used to in real life. This can be a very subtle effect or an exaggerated one as essentially it just helps to catch light and help show off the shape and detail of the object better.

(It can be a bit hard to see in the viewport at times with the default lights but makes all the difference when rendering with proper lamps)

Here is the bevel modifier with some optimal settings, increasing the value in the Segments slider will make the edge geometry start to approach what is more commonly called a Fillet, effectively rounding your edges. Do be warned however, as adding extra segments creates additional geometry.

Here is another look at how beveling effectively softens your edges.

Some advantages of beveling over other methods are:

• It's cheaper than subsurface, meaning it renders faster and weighs down your scene less.
• For hardsurface models, it softens or adds realism to your edges easily and effectively.
• It's faster to do and gives you more control when compared to other methods such as using creases and or subsurf with edgeloops.

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At the time of writing, this is now easier than ever. Cycles will have a Bevel Shader.

Example from Mike Pan on twitter.

Resource links

• Example renders https://developer.blender.org/D2803#65805
• Discussion thread https://blenderartists.org/forum/showthread.php?436279-V-ray-got-rounded-hard-edge-shader&p=3230688#post3230688
• More discussion and examples http://polycount.com/discussion/comment/2570081/#Comment_2570081

Answer 2

I've found that a good lighting rig goes a long way towards helping the realism of any scene. If you're looking for less harshness and a less geometric/calculated look, you should try enabling Ambient Occlusion in your renderer.

As you can see here, the modeling is rather basic (not to rag on the author), but the soft lighting effects of the ambient occlusion calculations reduce the sharpness.

Just keep in mind that this won't be a silver bullet; you still need other parts to make a good lighting rig, but that's a lot more involved than a single answer.

Answer 3

The Bevel method iKlsR mentioned is the fastest way, but possibly the most realistic method is to use two subdivision modifiers.

Using Subdivisions:

You need to have two subdivision modifiers, one as "Simple" (the first one in the stack) and the other as "Catmull-Clark".

NB: Subdivision modifiers are pretty heavy on viewport rendering, so if you don't need to see the final results when modelling, you can turn the number of divisions down.

Here is an example:

You can tweak the modifiers to get the results that work best for you. You can also use this along with the bevel method as it provides even more realism, though I must warn you, you need pretty good hardware to handle this in real time.

Here is an example with an actual, useful model (a Helicopter):

Rendered version:

Why Simple + Catmull-Clark?

Simple subdivision preserves the shape of your object, and in fact "enforces" the corners and "hard" areas of the object. However, it won't always give you a natural look. Catmull-Clark smooths as it subdivides, which is something you could do manually, but it is better with the modifier unless you want control over just which vertices/edges/faces are affected.

Answer 4

In addition to the good suggestions above, don't underestimate the impact of good textures. Even surfaces we consider to be "one-colored" and even, aren't. There are always small variations in the surface, either from wear-and-tear, dirt or just the material and manufacturing process in itself.

One classic trick is the "orange-peel-effect", which simulates the small bumpiness of, for instance, an orange. It's easy to set up, and is basically a bump map that is packed very dense, but with a very low depth.

Answer 5

realism is about carefully adding accurate imperfections. Whatever you attempt to model:

• Take time to examine the real object close up. Either using images, find macro shots or if you have the item, use a magnifying glass.
• Take note of small irregularities on the surface, maybe something bulges toward edges. (use a bump or normal map, or add geometry)
• Study how light hitting the object behaves as you rotate the object. Maybe some parts are shinier than other. Are there texture changes from rough to shiny? use a specular map, and adjust your materials to behave like their real world counterparts.

Objects rarely have uniform bevel / fillet radii all over, so the specials menu w has a bevel option that allows you to manually set the bevel segments for edges, hit F6 to see which settings can be tweaked. This is a desctructive edit (ie, not a modifier), so have a good look at the result and undo as soon as possible if it's not satisfactory.

Even subtle texturing and bump mapping are very powerful ways to make low poly geometry appear more lifelike.

A quick Flickr search of circuit boards, reveals an abundance of ways that circuit boards are infact less 'precise' than their design plans suggest. Stuff can be tilted, slightly bent. Fixtured and holes can be placed slightly to the side of the outlines. The bore-hole can be uneven, jaggy edged even.

Answer 6

Beveling is by far the easiest thing to do and will have a very positive impact on your realism.

The other answer showed how to bevel with the bevel modifier. If you want more control, you can bevel edges in edit mode using CTRL + B, then dragging your mouse until you have a desired bevel amount.

If you want to bevel a single vertex use SHIFT + CTRL + B

Answer 7

One method that is often overlooked is the Edge Split modifier with objects set to Smooth. When you turn on smooth shading Blender tries to smooth out all of the faces. The Edge Split modifier will smooth only that are less than a specific angle which is 30 degrees by default. You can also mark selected edges as "Sharp" and they will show as if they are Flat shaded.