Channel Packer - version 0.90

Transcription

1 Channel Packer - version 0.90 Pack your maps in a texture s image channels Link to updated documentation If you are reading this document inside Unity you can try to go to this link to read the updated documentation. Usually the online version is more updated than the published one. What is the Channel Packing If you look at a digital color image, you can see that for each image point (pixel) there are almost 3 values representing the intensity of primary colors that mixed together give the color for that point. These color intensities are normally stored as values between 0 and 255, so they can be stored as 8 bits. The three channels for the three primary colors (Red, Green and Blue) needs 24 bits of memory for each image point. In addiction there is another channel named Alpha that store the transparency for each image point information that is useful when you have multiple color layers that must blend together. The memory needed to store such images become 32 bit for each point and is usually recognized by an abbreviation like RGB+A, RGBA or RGBA32. During the 3D model elaboration, we use particular programs called shaders to display the aspect of his materials. The shader needs information about attributes of the material to display and usually get them from texture maps. These images are often in grayscale, and they fills the 4 RGBA channels with the same values. Channel packing is a technique which generates a texture using a different image for each of its channel: Red, Green, Blue and the transparency one, Alpha. The resulting texture is an image that contains 4 independent channels, each one with some special information that are later used by a specialized shader, to gain memory and to have faster operation: inside each texture we can insert up to 4 different images, managed and process at the same time. Channel Packer is a tool that allows to do that (and more) inside the Unity editor.

2 Changelog v.0.90 o Menu: now the tool is located inside the HoloGames Tools folder. o Batch mode: Added a special selector tag to allow selection of all unselected textures. v.0.86 o Fixed Argument out of range error when starting a batch processing and some texture is missing in one or more channels. o Output path: Added a check for missing path. If the specified path is not found, Channel Packer asks to create it. o Changing packing mode and then returning to a previous one recovers all parameters. o Batch mode: Changing packing mode now force file selectors application. o Batch mode: Added the Clear Worklist button to remove all textures from the Worklist itself. v.0.85 o Added a toggle to manage textures marked as Normal Map. v.0.84 o Typo on interface fixed. o Increased compatibility to allow working with unity from version onward. v.0.83 o New option to save as TGA Uncompressed, TGA Compressed or PNG32. o Added 4096 and 8192 to the list of output sizes. v.0.82 o Fixed errors in Gamma <-> Linear conversion. v.0.81 o Implemented a new way to get textures without read/write enabled flag. Removed all the related code, messages, etc. v.0.80 o First public release. Channel Packer v

3 How to start To open the Channel Packer window, simply select it from the Unity Windows menu, in inside the HoloGames Tools folder. The tool can be docked to other windows, if needed, to optimize the editor s layout. It was designed to be placed in the Inspector zone, but you can place it wherever you want. Chanel Packer Single and Batch modes Channel Packer works in two different ways: Single mode: used to generate a single texture, packing up to 4 input images; Batch mode: used to generate many textures in a unique operation, starting from a list of images; it allows to associate them to the needed channels and pack them in a texture for each association. Working in Single mode Basic information To produce a packed texture in Single mode, we need to insert some required information: Channel Packer v

4 Packing mode - you can choose between four packing mode o Standard: Albedo -> RGB Height -> A o MSEO Metallic -> R Smoothness -> G Emission -> B Ambient Occlusion -> A o NSO Normal -> RG or GA (using is a normal map toggle) Smoothness -> B Ambient Occlusion -> A o NSM Normal -> RG or GA (using is a normal map toggle) Smoothness -> B Metallic -> A Output Size you can select the desired packed texture size in pixels between 64 and 8192 pixels. The generated texture is always squared. Please note that an uncompressed 8192x8192 texture can use about 256MB of disk space. The time needed to resize and save textures is proportional to the selected output size; if you choose the same resolution of the input images the resize is skipped, resulting in a faster processing. Packed Texture name this is the name of the texture that will be generated. It will be automatically suggested on the input textures basis, but you can change it if you want. Output Path This is the path where the generated texture will be saved on disk. You can use the button on the right of the field to select it using an interface, or you can type it if you want. Be careful: the output path is the physical place where the texture will be saved, not the path inside your project. It is better to use the interface to choose it, to avoid to write files in the wrong place or where you have no write access due to security. Save as This is the image format used to save the generated texture. You can choose between TGA Uncompressed (Truevision Targa RGB Uncompressed), TGA Compressed (Truevision Targa RLE Compressed) and PNG 32 (Portable Network Graphic 32bit). Channel Packer v

5 Managing the input channels According to the selected packing mode you will have 2, 3 or 4 channels to manage. In the following example you can see the required channels for a Standard packing mode: From left to right you can see a frame for the channel process options and a squared space to select and preview the texture As usual in the Unity editor, the texture preview allows to select the texture by drag & drop (you can drag a texture from the project and drop it directly on the preview) or by using the Select button. The available options are: Invert Texture if this option is selected, the texture will be inverted during the packing: the colors will be inverted, the white will be black and so on. This option is useful when you need, for example, to convert a smoothness map into a roughness one and vice versa. Is a Normal Map This option (available when using NSO or NSM packing mode only) allows you to use an image tagged as Normal Map as input. This kind of images has information packed into Green and Alpha channel instead of Red and Green. Input Channel selection Allows you to view which channel from the input texture will be used to make this channel in the packed texture. If only one channel is used for that you can select which one. The number of used input channels depends from the current packing mode. Channel Packer v

6 Color selection Allows you to use a solid color instead of an input texture and insert in this channel of the packed texture. You can enable this option by checking the Toggle Color/Texture option. You can use directly White, Black, a 50% Gray color, or you can choose directly the color you prefer using the Custom color picker. Unchecking the Toggle Color/Texture option the previous texture will be recovered. Packed Texture generation. After you select an output path, and after you put the textures in the input channels, you should be ready to generate the packed texture. The button to execute the final texture generation will be shown only after that all the requirements will be fulfilled. This is the requirements list: All textures or colors needed must be inserted; The Output path must be specified; The Packed Texture name must be specified; When all the requirements are fulfilled a button like this will appear: When you press it, all the input images are scaled to the selected output size, then are inverted, if you choose inversion, and are inserted in the output channel of the packed texture. Channel Packer v

7 Finally the new texture is saved on disk with the chosen filename and.png extension (or.tga extension if TGA format was selected), in the folder previously specified. Be careful: if another file with the same name exists in that folder, it will be overwritten. Working in Batch Mode The Single mode is perfect when you want to pack just a few textures, but if you want to pack a lot of textures you will prefer the Batch mode: It allows you to operate on more of them at a time. Basic information To produce packed textures in Batch mode, you need to insert some required information. We already have described some of them in the previous chapter: Packing Mode; Output Size; Output Path; Save as. The name of the packed texture is useless because we will generate a lot of them, in his place we will found Output Texture suffix the suffix that will be added to each input image name to build the name of the packed texture. In this way the name of the generated textures will be formed by the name of the input image inserted in the first available channel followed by the suffix defined here. A default suffix is defined for each packing mode. Channel Packer v

8 List of textures to be processed Making a Worklist To specify the textures that you want to convert, simply select them in your project and drag them on the worklist zone of the Channel Packer interface. You can select textures from the project as a group or one by one and you can add them to the list a little at a time. If you add to the Worklist one or more textures by mistake, you can easily remove them just clicking on the little button on the left of their name, or you can use the Clear Worklist button, located just below the Worklist, to remove all textures with a click. The Clear Worklist button is visible only if there are textures in the Worklist. Channel Packer v

9 Managing the input channels How to massively assign textures to a channel. Due to the selected Packing Mode, you will have 2, 3 or 4 channels to fill with the textures you want to process. In the Batch Mode you can t directly select textures and assign them to channels; you must use some selectors instead. For each channel you can specify a selection criteria called selector. This criteria act as a filter and is applied to the name of all textures in the Worklist: every texture that has a name matching with the criteria will be added to that channel. Here there is an exemple of selectors for the MSEO packing Mode: You can use 2 special characters (wildcard) to write a selector:? (question mark) - This can represent any single character. If you have specified something like hd? Channel Packer will look for hda, hdb, hdc and every other character in that position. * (asterisk) - This can represent any number of characters (including zero, in other words, zero or more characters). If you have specified a cd* it would match cda, cdrom, cdrecord and anything that starts with cd also including cd itself. m*l could be mill, mull, ml, and anything else starting with an m and ending with an l. There is another special selector ## (double hash) Can be typed in one channel only and is used to put in that channel all the unselected textures. This can be useful when you have a set of textures that has no special characters defined for texture naming. Therefore if you type *_met* in the selector for the Metallic channel, all the textures that have in the name _met in any position will be selected; if you type instead *_met without the final asterisk only the textures having names that end by _met will be selected. You can specify more criteria to be used as channel selector by using, (comma) or ; (semicolon) as separators. In this way you can select more than a single textures group for a channel without having to rename them. Note the ## to get all the unselected textures can be used on a channel only. Channel Packer v

10 Managing the input channels - Preview It s obvious that selecting textures by their names, make difficult to imagine what the Channel Packer exactly will perform when we'll start the process. To solve this problem we implemented an output preview window, available if at least one texture is added to the Worklist. In this window you can see the following information: The texture list for each channel. This is the result of what you put in the channel selectors; The list of output names. Here you can see how the packed textures will be named; Missing textures are represented with --- (three dashes). The preview is updated in real time so you can use it to have a visual feedback of what you type in the channel selectors or in the output suffix field; the read/write status changes and the worklist texture addition and removal is reported in the preview windows too. Using the preview window you will have access to the channel options too. For each channel you have the same options already described in the Single mode section, but here they will be applied on all the textures for that channel. Working on the Input channel selection or the Color selection will open a foldout for every channel, to maintain the list of textures aligned and continue to visualize their associations. Please keep in mind that when you specify a channel option in Batch mode, all textures in that channel will be affected. Channel Packer v

11 Selecting a color to be used instead of a texture, for example, imply the generation of a virtual texture that will be used to replace all texture in that channel; to easily recognize this, Channel Packer will use the selected color as texture name, as you can see in the figure: N.B. If you change your mind and want to remove the virtual textures for a channel, simply uncheck the Toggle Color/Texture option. Channel Packer v

12 Generation of Packed Textures At this moment it should be possible to generate the packed textures. The generate button remains hided until all the requirements will be fulfilled and all validations passed. Requirements list: Textures or colors must be assigned to the various channels; The Output path must be specified; The Output suffix must be specified; When all is ok, the generate button will be visible, just below the preview one: Clicking on it the process will start and every texture assigned to a channel will be scaled, if needed, to the specified output size, will be inverted if you selected the inversion for that channel and will be inserted in the desired output channel on the base of the chosen Packing mode. Finally, every generated packed texture will be saved on disk on the selected folder using the generated name and with.png extension (or.tga extension if you selected to save in TGA format). Be careful: if another file with the same name exists in the output folder, it will be overwritten. Channel Packer v