Beginner's Guide to Rendering

General Tutorials - UV Mapping

A Primer for newcomers

What's the difference between an average render and something amazing? What makes a render really stand out from the pack? In this article we are going to break down all the elements that support having that awe inspiring masterpiece. Let's look at some of the aspects of putting together our scene...

• Subject matter

• Lighting

• Light settings

• Camera settings

• Camera angle

• Render settings

• Textures

• Shading

• Post work

Keep in mind that this is only a primer. It represents nine aspects of getting to a render you can be proud of. I won't attempt to go into detail about any one of the subjects as a whole book could be written about each and every one. Think of these nine aspects as nine pillars upon which to build your masterpiece.

Subject matter

Is this interesting? To be more specific - is this interesting to me or is it interesting to others? There's a world of difference between the two. The latter is more likely to land you a job by way of your portfolio, sell your products, or attract praise.

Lighting

We are talking here about the positioning of the lights. I can't think of anything that will affect the mood of your scene more. I won't give any advice to advanced users on this subject because this  part is geared more toward newer artists. Start by mastering a basic point lighting system. This is the most common type of lighting system used in movies. It consists of a key light, fill light, and a back light. There is a great flash tutorial on this here.

You can use either spotlights or bulbs for a basic three lights set up.  I most often use spot lights.

Key light – This light is meant to illuminate your subject place at approximately 30° from one side of the camera and angle it down approximately 30° from above your subject.

Fill light – This light is meant to cut a harsh shadow created by the key light. Position this light in exact opposition of your key light and lower the brightness so that it is approximately 60% as bright as the key light.

Back light – This light  is positioned behind your subject and raised above the subject. Next angle it down at the subject to create a soft shadow. The purpose of this light is to separate your subject from the background.

Remember this is just a starting point, it's geared toward indoor lighting and not ideal for outdoor lighting.

Once you have your lights set up now it's time to set the mood. yYou can do this by adding additional lights or by adjusting the fill light, mostly it's positioning. You can then adjust light intensity and color. You'll be amazed at the results you can produce with this simple lighting setup. In my opinion over lighting is rampant in the cg community -  what I mean is the use of 10, 15 even 20 lights when three would have been sufficient. A few skillfully placed lights will often times provide better results and speedier renders than a slew of them.

Lighting settings.

There are a myriad of different lighting settings for each light, the settings you will have access to will depend on your software package. Common settings will be:  soft shadows, ray-traced shadows, the ability to adjust the color and strength, IBL or image-based lighting, and HDRI lighting. You may also have access to caustics, volumetric lighting, diffuse, and specular settings. When you configure the settings for highger render quality this will also increase the render times.

Ray trace shadows take longer to render than soft shadows, IBL lighting takes longer to render than soft shadows or ray traced shadows alone. HDRI lighting will take the longest to render.

Camera settings.

Depth of field is the setting that will cause areas in the background or foreground to blur. Sharpness will decrease both behind and in front of the subject when the focal distance is set to that subject.

F-stop

As the number gets higher less light is let into the camera and it affects the depth of field in that you achieve more focus. A lower number will allow more light in and affect the depth of field as it will give you less focus. The image above uses a combination of f-stop and depth of field.

Camera angle.

My suggestion here is simple - watch a movie and find a scene that best represents the emotion or mood you want to portray in your render and notice the camera angle. Good movies are perhaps the best source of reference for camera angles, the challenge is that we are generally busy watching the movie and not paying attention to the camera angles. Best example of this might be a scene where the hero is dangling from a cliff edge. What's the best angle? Would it be a close-up? While this might be a good way to represent the emotion of the character it's probably not the best way to represent the gravity of the situation. How about a wide-angle shot? A shot from the bottom of the ravine peering up at the dangling hero? Perhaps a shot straight down? It's your render. You decide and know that you have options - Don't be afraid to save your camera and try several different angles with other cameras.

Render settings.

Become familiar with the rendering options of your particular software package and the effects of each and every one of those options. Many times people new to 3-D will increase certain render settings unnecessarily and accidentally increase their render times without benefit. A good example of this is the shading rate option. I rarely notice any significant benefit with the shading rate lower than .3. Again this will vary depending on your software package. If you have reflections, refraction and more transparency you'll want to increase your ray trace bounces. On the other hand there are times when you will have no need for this.

When you have your render settings adjusted for your final image render a small portion of the scene first - you may be surprised to find some anomalies. This gives you the opportunity to adjust the settings accordingly without having to wait for the long render to finish only to be disappointed.

Expect long render times. Of course this is dependent upon your machine and a quad core renders faster than a single core.

Textures

If you render a low resolution texture or high-resolution texture that is of low quality you're not going to get the results you looking for no matter what. The difference between your renders and those of someone else may simply be the quality of the textures.

Shading

If your software package provides you the option of using shaders I highly recommend that you learn how to use them. Shaders can often times be combined with your textures to enhance them and hence your render. Ambient occlusion, specular, diffuse, glow and many other settings go a long way in enhancing the look of your scene.

Post-work

There are many different methods in doing post-work. You can render in layers, you can render separate scene elements to combine them later. Post-work will provide you the opportunity to enhance or fix colors to adjust lighting and the list goes on.

Wrapping it up

I hope that you found this article useful in providing you with both a checklist and a way to structure the process of producing a good render in your mind.