Create a new Bitmap object by double clicking on "Bitmap" in the Object panel, or by selecting the "--- new Bitmap ---" item in the "Bitmap" pulldown in a Texture or other object. The first thing you will see is the "Open Image File" file dialog.
If you want this Bitmap object to utilize a bitmap file already existing on your hard drive, use the file dialog to select the bitmap file now. Note that the file dialog only allows you to select files from one of the bitmap file formats supported by K-3D: Windows Bitmap (bmp), Targa Image (tga), and JPEG (jpg). You can use the "Files of Type" pulldown box to filter out individual file formats, or you can leave it set to "All Image Files" (the default). Select a bitmap image to load. The Bitmap dialog will open, displaying info about the file you just loaded. The File Path control displays the location of the image, while Width and Height display its dimensions. Note that these three controls are all "read-only" ... you cannot change their values because these parameters are determined by the contents of the file on disk. You can click the View button to open a BitmapViewer that displays the Bitmap image full size. When you click on the "Alpha" tab of the Bitmap dialog, youll see similar information displayed for the images alpha channel. In this case, the File Path is blank, and the Width and Height controls contain the same values as those on the "Image" tab, because by default, the Bitmap objects alpha channels is being drawn from the same file as the image. If an image does not contain an explicit alpha channel, the Bitmap Object will provide a default, 100% opaque alpha channel. You can click the View button to open a BitmapViewer that will display the Bitmap alpha channel full size as a greyscale image. If you move to the "Preview" tab of the Bitmap dialog, you will see the image displayed as two squares: the square on the left is a thumbnail of the Bitmap image, and the square on the right is a thumbnail of its alpha channel.
If you wish instead to generate a custom procedural bitmap with this Bitmap object, hit the Cancel button in the file dialog that is opened when you first create the Bitmap. The Bitmap dialog will open. Note that File Path is blank, and the Width and Height controls are set to "0" for both the "Image" and "Alpha" tabs. Also note that the Width and Height controls are no longer read only: you can enter values for Width and Height to make your procedural bitmap as large or small as you like. Note that the Width and Height values are always the same for the image and alpha channels - when you change a value on one tab, the values automatically change on the other. You use the Procedure pulldown boxes on the "Image" and "Alpha" tabs to specify which algorithms should be used to control the image and alpha channels respectively. When you open either Procedure pulldown box, you will see a list of options including a series of "--- new ProcedureType ---" items, where ProcedureType is the name of a Bitmap Procedure object installed on your system. At a minimum, you should see "--- new Checkerboard ---", "--- new FractalNoise ---", and "--- new Marble ---" in the list, since these are the three Bitmap Procedure objects shipping with K-3D as of this writing. Selecting one of these items will create a new Bitmap Procedure object of the given type, and assign it to the image or alpha channel, depending on which you are working with. The pulldown box list will also contain a list of names of all the Bitmap Procedure objects that have already been created within the current document. This allows you to share a Bitmap Procedure object between two Bitmap objects, or between a Bitmap objects Image and Alpha channels.
When you create a new Bitmap Procedure object, its dialog will open and you can alter its controls in the usual fashion to alter the image it creates. If you close the Bitmap Procedures dialog, you can reopen it either by double-clicking the LMB on its name in the Hierarchy Panel dialog or by clicking the Edit button on the appropriate channel tab. As you make changes to a Bitmap Procedure, youll see the Bitmap dialog "Preview" tab update automatically, along with any open BitmapViewers, and all Camera.
If you want to change the image file that a Bitmap utilizes, or you want to reload the same image file after making changes to it in another program, select the "--- new File Image / Alpha" in the Procedure pulldown box. A file dialog will open and you can select the file.
If you want to use separate files for the image and alpha channels, simply create the Bitmap object, then use the "--- new File Image ---" item in the "Image" tab Procedure pulldown or the "--- new File Alpha ---" item in the "Alpha" tab Procedure pulldown to specify separate files. This will allow you to use Bitmaps with alpha channels even if you dont own paint software that allows you to edit alpha channels. Note that the files must have the same width and height.
Finally, you can mix-and-match bitmap images with procedural images in the same Bitmap, with the caveat that the width and height of a bitmap image always takes precedence over the width and height you may have previously specified for procedural images.
Once created, your Bitmap object will be available for use by other K-3D objects. The manner in which an object uses Bitmap objects will vary, although most will use it "through" the use of a Texture object.