Fundamentals of Rendering: 02_ Converting 3d into 2d


camera taking a photographHi! As in the last post, I made an introduction to rendering and we talked about ‘Engines’. Now in this post, we will talk about a process of converting the 3d data into 2d.

Let’s Talk about some output devices first. Like the computer screen, monitors, printers, projectors, etc. If you have observed them closely, non of these device produce actual 3d output. Our PC screen is flat, the printer paper is flat, even the projector projects on a flat background. When we see a film or read a printed paper, we see only the surface of the screen or paper. We don’t actually consider the thickness. That means all of these devices are based on 2d projection system, not on 3d. Even the 3d stereoscopic film’s output is flat and 2d. Although looking through the coloured glasses it appears to be 3d.

On the other hand, softwares like Blender, 3dsMax, Maya, Softimage, etc. are completely based on 3d world. These softwares stores all the information in 3d geometrical method. They use 3d co-ordinate systems to calculate distances etc.

Now, when it comes to produce some image or video, it then becomes necessary to translate the 3d data into 2d, so that the output devices can understand it. So that it can be displayed on the screen or we can get print from it. This translation is one of the most important process that the ‘Rendering Engine’ does.

To understand this more, lets take an example of a photo camera.

camera taking a photographWe often take photographs of our friends, family members or beautiful scenery around. Obviously our entire world is 3d. Each and every object around us has got some thickness to it. But the photograph we take is a flat and 2d projection. The camera ‘sees’ the 3d world, takes the projection on a 2d and flat film, which in turn makes the photograph. We need not consider the thickness of paper here to see the picture.

photograph taken from cameraIn exactly the same way (in CG), a camera makes a 2d projection of all the 3d objects in front of it. The render engine develops an image of this 2d projection, made by the camera. And we get output in form of image or video that can be seen on some output device.

I think we got the ‘Picture’ clear now!

So lets stop here today. Please leave your comments or suggestions in the reply section below. Click the ‘Follow this Blog’ button on the right-side column to get regular notifications of the blog updates. And also don’t forget to share this to your friends who has got interest in learning computer graphics!

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One thought on “Fundamentals of Rendering: 02_ Converting 3d into 2d

  1. Pingback: Fundamentals of Rendering: 03_Resolution | mahesh deshpande

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