What we want ?
We want to set up the lighting of a computer graphic scene.
What do we need ?
We need to render separate pictures for each light in the scene.
Pictures must have the same size, in pixel.
The lights are white, with relative high intensity but the pictures
must not be overexposed.
In this case, we have : A : ambient light, B : front light, C
: fill-in, D : back light.
How to ..
To set up the lighting, we need control of
the intensity and maybe the color of the lights.
But first, enter the size of the project, say 768 by 576.
(In the rest of the document, I will use 320 by 240 picture, it's
easier to include in this file.)
Now we will construct the list
of actions that AddLight must do.
First, load all the pictures. Hit the [Add one line] button.
This will add a line in the list.
There is no real action set at this point, the line is labelled
"No operation".
The thin red outline means that this line is selected.
Now we can hit the [Modify] button to choose the right operator
for this line.
The Operator window opens.
Click on the [Load] button, in the File operation frame, then
click [OK].
You can also double-click on the [Load] button, this will automatically
close the Operator window.
You see now that the panel, at the middle of the screen, has
control tools, in this case, a button, a checkbox and a number
input.
The controls depend on the operator you have selected.
Hit the [Browse] button to select the first picture, with the
ambient light.
We will work with a single frame, so leave the "Sequence
of frames" checkbox unchecked.
At the right side, you see the Picture frame. This tells AddLight
on which bitmap the picture will be stored, in memory.
For the load operator, only one bitmap is needed, the destination
one, which is set to A. An operator can work with one or two bitmaps.
The result is always store in the bitmap designed by "Destination",
the source is unchanged.
Repeat this sequence of operation for each picture, but set the destination bitmap to B for the front line picture, C for the fill in and D for the back light.
Now, we need to combine the light from all the pictures into
a single frame.
Add a new line and modify the operator to [Add] from Arithmetic
operation frame, in the operator window.
Now that you know what buttons to use to set an operator in a
line, I will only say "use Add".
For this operator, you must set a source and a destination bitmap.
Note the numeric slider that tells you how much of the source
is added, in percent.
We decide to add the first picture to the bitmap E. Select A for
Source and E for Destination.
Repeat this operation for each picture. Select the appropriate
Source bitmap for each picture.
Hit the [Show] button to see picture E.
The picture window shows, click the E button. You can also
see what is in the other bitmaps.The bitmaps not used are ghosted.
You can see the final picture, bright and overexposed.
For each picture, we will use [RGB balance] operator. This will
make it possible to modify the color and the luminosity of the
pictures.
This operation must be done to the A, B, C and D pictures before
we add them to E.
Use the [Move up] and [Move down] button to modify the list order.
Be sure you see the E picture in the picture window.
Now it is time to set up the lighting.
Select the [RGB balance] line you want. You will note the 3 sliders.
By default, they are set to 0, that means no change.
If you slide to the left, the value will move to -100 that means
colors tend to BLACK.
If you slide to the right, the value will move to 100 that means
colors tend to WHITE.
The picture is refreshed when you release the mouse button from
the slider.
Here are 5 examples of what you can get.
Now you have your lighting set right. You need to save the
picture.
Use [Save] operator at the end of the list, with E as destination
picture.
Use browse to select or type a filename.
The final list should look like this ...
For now, nothing has been saved.
Nothing is saved when you are setting up a list.
To really execute the list, set the Frame number to 0 (0 by default)
and hit the process button.
Now it is done.
If you want, you can save the list to a file using the [Save list]
button.
AddLight list files have .adl extension.
Attention : the pictures are not saved in the file !