Know About Surface Rendering in Computer Graphics

As a computer animation graduate, I personally know the time and struggles that go into creating the perfect 3D scene. I also know what time it takes to render out a scene, not to mention the stiffness that comes with sitting and waiting for the final result. The most elaborate the scene is and the higher quality you choose, the longer it takes to finish ONE round of rendering. Yes I said one!

What is Surface Rendering?

Rendering is when you take a 2D or 3D model or scene (depending on what your creating), and turning it into an image. In order to create any image in any scene, you must have your cameras and lights set up just right in order for the image to render correctly.

The term rendering can also be used to explain the calculating effects that creates the final output in film editing.

What is rendering used for?

There are two main types of rendering:

  • Pre rendering: This is used in films and movie making.
  • Real time rendering: This is used when creating a 3D game.

What does it take to produce a beautiful final image?

The requirements of creating a perfect end to your long, time consuming wait when rendering relies strictly on your skills with everything else in the program. If you do not know how to work with your tools correctly and build a perfectly lit scene then the rendered image will come out as a shock to you.

Surface Rendering

When looking at your finished 3D scene, you will see tons of color (if a skin was applied). Wether it be a lambert or a metallic surface, the models in your scene are not what your going to see in a final rendered image. If done correctly, it should come out as it would if it were a picture you took with your camera.

When you render out your first image, use that to correct all your mistakes. You may find that a red surface in your scene may shows up as black in your image or maybe your using the wrong light setting to brighten your 3d scene or model. The number of things to look over can seem overwhelming to someone who just doesn’t have the patience or knowledge. Those dedicated to sitting at the computer all day will have to look over these things with each image that is rendered out:

  • The shading: Check the shading on everything that offers the option.
  • Texture and bump mapping: Check to see if your texture or map colors are the problem and either lighten or darken it according to what you feel looks best.
  • Lighting: Check your lighting options. You may find that a simple fix of the lights will do the trick.
  • Shadows: ALWAYS include shadows. This is something to keep your eye on as you render each scene. If you change your lighting or if you change the color of the ground, it will change your shadows. There are other things that will contribute to that as well.
  • Reflections: Do you have any shiny objects in your scene? Windows, glass, and such objects require you to closely monitor the reflection status. Did your last render take away the look of transparency in anything that needed to have it? Is it as translucent as you need it to be? Also, check your refractions (the bouncing light in an item like glass). Last but not least, check your indirect illumination settings (the tool that spread light through reflection on objects). Are they contributing to to much light with in the scene?

As you work through your long day of rendering, remember to try one thing at a time and undo what doesn’t work for you. Save constantly because this part of the project can make your software crash depending on your program.

As more updated versions of this type of software emerge, so do new features for rendering your image. The latest to hit the programs are rasterization, ray casting and ray tracing.

  • Rasterization: uses geometry to project the objects in the scene onto image plane without the use of extra effects.
  • Ray casting: reduces artifact by calculating the image, based only on geometry and some basic reflection intensity laws.
  • Ray tracing: This uses what is called the Monte Carlo technique to get better results but at a slower speed.

What do I have so many pixels all over my image?

The one thing to constantly watch is your sampling. You need to fix this more often than anything else with in the scene. In order to get a smooth, non pixelated image, you need to keep your samples as perfect as you can.If your not careful and you use the wrong algorithm when rendering your scene, then your going to get an image that you will be fixing for hours. There is a term called “aliasing”, which is the rough jagged edges in your final image. The wrong sampling leads to major aliasing.

What if I just want to render one object in the image?

You can definitely do this. When your render box pops up, you should have the option to not only render the whole image but box off the section you want to change. There should be a specific button just for that command. You should also have the option to keep any images for comparison. This is a “MUST DO” when your working on this part of the job.You need to always compare the new render to the last one. It may look better at first but after a second look with the previous one, you may find that it was actually worse.

If your just beginning in this world of 3D modeling and creation, then you will certainly be lost. I remember how overwhelmed I felt when I started school in the field. I was taking excelorted courses, where each class had to be finished in a month. When I did my first rendering project, I was impatient and very confused about everything I was learning and reading. After a few classes, I felt more comfortable with the programs I was using and the things I was learning. My point is not to lose your mind over this. The one thing I had to get over in order to create my cool creations was the fact that I thought I was waisting time when rendering. It can be an extremely long process depending on what your doing and how good you are. The final results are always the prize.