Rendering By The Slice

There are two ways to think about the “slice function”…

One way is that Apophysis does it’s own internal slicing when you have an image render that requires more memory than you have installed on your computer. Say your image render needs 500 MB but you only have 364 MB of physical RAM available. If you check the box to limit the memory usage, Apo will automatically break the task into “slices” and render them one at a time and compile them together into one image when the process is done. Say you check it and use the value of 128 MB as a limit, as it begins working you will see a note at the bottom informing you that it is working on “slice 1 of 4.”

The second way is to slice up a big image manually so that it doesn’t render all at once, occupying the next two weeks of your computer time!

The goal is to render in smaller time segments so that You can get full access to your computer once in awhile and eventually still get that larger render accomplished. After they are rendered they get assembled as layers in Paint Shop Pro or Photo Shop. The following gives directions for working in PSP.

Note:

The following instructions are based on certain assumptions about how Apophysis is being used.

  1. The renderings being discussed are rendered without transparency, or if rendered with transparency have been combined with a black background so that what is being worked on is no longer transparent. The reason this is important – transparent renderings cannot be overlapped and combined as described here. To combine transparent renderings they will need to be trimmed for an exact edge-to-edge fit. The same may be true if the desired background is a gradient of colors or a non-black background.
  2. The alignment options assume that the Adjust panel/Camera tab/Rotation control remains at 0 (zero). If this control is not ZERO it will change how the alignment of the slices can be accomplished. In most cases, any rotation of the flame can be accomplished without having to make use of the “Camera Rotation” control.

Open one of your rendered slices and enlarge the Canvas or start a new image that is big enough for all your layers. Load each image as a New Layer, and align the layers using “difference” as the method which makes the overlap areas turn black when it’s properly aligned. Assuming your background color is BLACK, change the layer properties to “Lighten” which allows the layers to blend and minor differences from render to render are not a problem and won’t create a visible line. When you are done, flatten all the layers into one layer.

Slicing

Here’s an example. Say you want an image that is 3000 pix wide x 2000 pix high. The “Scale” property in Apo is directly tied to the “Width” factor but NOT tied to height. So the key here is to leave the Width=3000.

The slicing will be done only on the height factor.

This example has a finished image that is 2000 pix high so let’s make 10 slices, each slice 250 pixels high. The reason is that you want some overlap for the later compositing process. You also want to make sure you capture the full desired height of your flame. If there is extra area you can easily crop the assembled image.

Start by correctly scaling and centering your desired view in the preview window. Then set the Image Width and Height to the overall values you want, for this example it is 3000 x 2000, click update, then save your parameters.

Before you start slicing you need more information.

Go to the “Adjust panel” and click the “Camera” tab. Make a note of what values exist for the “X position” and the “Y position”. These represent the center of your desired view for the whole thing. For this process you will be changing the “Y position” values, but do NOT change the “X position” values.

The next task is to find out where the top of your image is and the bottom. You do this in the Main panel preview window.

In this example (yours will be different) my overall center is Y=0.005.

Click and drag your preview from very near the top of the preview window and approximately in the center from left to right. Accuracy here is not important. Drag that point down till your pointer is as close to the very center of your preview window as you can gauge it by simply looking at it. Release the mouse, and the “Y position” value will update in the “Camera Tab” of the “Adjust Panel.” Write that value down as it’s the location of the top of your image.

In this example the value is Y= -0.997. (yours will be different)

Now click near the bottom of your preview window, which is where the actual center of your image is at the moment, and drag that point all the way to the top of the preview window. When you release the mouse, the “Y position” data will update showing the location of the bottom of your image.

The bottom of this example is located at Y=1.061. (yours will be different)

Using the calculator, the distance between the top and bottom is found by adding these numbers together, and ignoring the minus sign for the top value. For this example the total distance for Y=2.058.

We want 10 divisions and we will start at either the top or bottom. That leaves 9 increments to fill up the rest of the space. In this example let’s start at the top and work down.

2.058 / 9 = .2286667 (rounded off)

This is the incremental distance between the centers of each slice.

Starting with -0.997, add your increment of .228667 and get -0.768333.
Next, add the increment again and get -0.539666, and so on until the last increment yields +1.0610003. You now have the centers for each of the 10 slices, each of which will be 250 pixels high.

Now you’re ready to set up the slices

Go to the “Adjust Panel” and click the “Image Size” tab. Make sure that the check box for “Maintain Aspect Ratio” is UNCHECKED! If you followed all the directions above the Width will show 3000 and the height will show 2000. Select the “Height” value and change it to read 250. Click the “Apply” button and the preview should update to a very wide but not tall slice, 3000 x 250.

Next, click the “Camera” tab and go to the “Y position” box. Eliminate the value already there and enter the value for the top of your image. In this example that would be -0.997. If the number already there has many digits you might have to click and drag carefully to select the whole thing and use -backspace- on the keyboard. When you’re sure it’s clean, enter your top value. Then click -Enter- on the keyboard.

The preview window should now be positioned so that it is centered on the top of your image. Save this parameter-set using an appropriate name, and a number designating the first of 10 slices.

Go back to the “Y position” box and enter the next position down in your list. In the example case, -0.539666. Click -Enter- and then save the parameters as your 2nd of 10 slices. Continue till all 10 are saved.

At your leasure, select one of those parameters and render it. When they are all rendered, assemble them in a graphics program.

 

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