T U T O R I A L

Generating landscapes with heightfields

· The most popular thing to do with HFs is to create landscapes, mountains or rocks and that's what we are going to do now. What do we need to get a decent, soft and mountainous landscape? Well - we need an image, with smooth color- transitions and not too bright or too dark parts in it (otherwise we would get a HF with great differences between the single altitude- levels). Some of the »Marble«-, »Agate«- or »Granite«- textures produce excellent HF-images, when rendered with a good »antialiasing«-value. Now, here is the guide, to accomplish our task ...

· We will use the texture »White_Blue_Agate«, which should be part of your texture- library, to create the needed HF-image. Step 1: insert a unit-size box into an empty scene and assign this texture to the object.

Step 2: create an omni-light, move it to the position X=0, Y=0, Z=-4 and set the color to 0.70 for the R-, G- and B-channel. Step 3: create a camera and adapt the position and the field-of-view«-settings, so that the camera-view shows nothing else than the box. Step 4: render this scene, rename it and save it as a new scene afterwards.

Step 5: delete the box, create a HF-object, using the TGA-image, you have just rendered and scale the HF until it fulfills your needs.
Step 6: assign a texture to the HF and render it - here we are: your first landscape!

· Now take your time and study the pictures above, to see the relation between color and altitude.


Additional heightfield options

· The HF we have just created looks quite nice. As you could see, a HF is a very flexible object, even though it has got only one parameter more than drawing primitives. This parameter is called »water-level« and can be accessed in POVLABs »manual setup«- dialog by clicking on the »parameters«-button.

· The »water level«-parameter specifies the height, at which POVRAY will start to render the heightfield. All parts lying beneath the water-level will not be rendered and stay invisible. Possible values for the water-level range from 0 to 1, where 0 stands for the bottom and 1 for the top of the HF. For example: specifying a water-level of [0.5] will leave the lower half of the heightfield unrendered.
Chapter B/Page 3
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This page was last modified on: 1996-07-27 		Mail to the author of the POVLAB-Tutorial:
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