The texture node itself is quite simple. It basically consists of another node, which will define exactly what type of texture is mapped to the object. For now, we will be using ImageTexture nodes. In the imageTexture, the most important node is the URL node. This is a multi-string node. Note the square brackets. Inside the brackets, you place the url of the image you want to have mapped to the shape. The url must be placed inside double quotes, and must be a valid url of a graphic file in standard url format. It can point to a gif or to a jpeg. Animated gifs will NOT work (although later I will show you an alternative.) Gif files with transparent backgrounds are fine, and are used quite frequently. You can see that there are three main ways that VRML tends to map images to surfaces. It can do a rectangular 'stretch and squash' as you can see on the box shape. On spheres and parts of cones, it does a 'distortion' to try and map the entire rectangular shape to the non-rectangular surface. As you can see, we can use this distortion to our advantage. If you examine the bottom of the cone with an image mapped onto it, you will notice that VRML also occasionally 'clips' an image. In effect, it draws a rectangle around an image, and simply shows the parts of the image that are are on the surface. So the bottom of the cone is not distorted, but only the center of it is shown. As usual, you will really need to look carefully at this yourself to understand the phenomenon. It really isn't that difficult to understand once you've played with it a little bit. To do this, make an image (or two,) with a transparent background. Try to center the image along the y axis. When you design the object in VRML, make it two boxes in the same space. Make one of the boxes REALLY tiny in the z axis, and the other really small in the X axis. Map your texture onto both of the boxes. Source.


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Last Modified: April 18, 2016 @ 7:09 am