### 3D Parameter Window – Transformations Tab

Fig.: 3D Parameters – Transformation Tab

• UpDown
Well, just as the name implies, this parameter lets you move the 3D view up or down.

Within the program this parameter just defines a constant, which is added to each height.

• Ystretch
Hard to explain. Well, due to the projection mode used in ChaosPro (i.e. orthogonal projection) the perspective effect of such views is not that good. In order to compensate this some parameters have to be introduced. One of these is this YStretch. It simply stretches the image in y-direction, i.e. to the back, improving the perspective effect of the images. Normally a value of 1.6 is good.
• FrontMult
BackMult
Again, in order to improve the perspective effect of the images, these two parameters are available. Normally an object, which is twice as far away as another object, seems to be half the size regarding the other object. But with orthogonal projection all objects have the same size. So FrontMult and BackMult exist: Suppose an image consists of 200 lines. Then ChaosPro transforms a row. It starts with the first pixel (the frontmost one), calculates its height and then multiplies the height with ‘FrontMult’. Then the second pixel is transformed, the height is calculated, and multiplicated with FrontMult + (BackMult – FrontMult) * 1/200. ChaosPro continues this way until the last pixel is reached, there the height is multiplicated with FrontMult + (BackMult – FrontMult) * 200/200 = BackMult.

So normally FrontMult should be 1, and BackMult 0.7, so objects more far away than others appear to be smaller.

• XMin, XMax, YMin, Ymax
These values simply define the scale of the graph display area below.
• Graph area
You may have wondered what this strange graph is ment for. Well, it lets you view and change the most important parameters for creating 3D views: It lets you define how buffer values (well, think of those values as the colors of an image) are transformed into heights. The most easy method is simply that height of pixel = color number. But that’s the most idiotic transformation possible due to the nature of fractals.
The graph displays knots, and you can move those knots. The different knots then are interpolated using a cubic spline. This method lets you easily change the transformation function.
This method is very powerful. If you have increasing buffer / color values, you may decrease the heights assigned to those values, which may result in a nice valley appearing instead of a plateau.
• Suggest
Well, if you played around with these values, then you may have noticed, that it is quite difficult to get a good starting point. Often the 3D view only consists of spikes. Obtaining a good starting point is the biggest challenge. Often it is impossible. But I teached ChaosPro to calculate a suggestion. So if you click onto the button Suggest, then ChaosPro will try to find a good starting point.
• Show Spline
This button changes the scale so that the whole spline and all knots are visible.
• Reset
Resets the scale to XMin=0, XMax=200, YMin=0, YMax=100.
• Fix horizontal value
Does what it says. When selected, ChaosPro lets you move knots only in vertical direction.

One note: If you create 3D animations where the height transformation function changes, then please make sure that each keyframe has the same number of knots. The knots may move in x and y direction and are interpolated correctly.