Download is at the end of this long post!
Here is the new and enhanced final version of the Canvas resizing tool BCAST.
WHAT DOES IT DO???
The plugin offers preset’s for common screen resolutions and media ratios. If you would like to design a Business Card and would like to have a canvas size which allows distortion free view of your final product, then you can do that now without unpacking the calculator. Pull open the Portrait or Lanscape tab for the Paper’s and there you find the settings. The canvas will automatically maximize after setting the dimensions.
Marcus Civis was so generous to donate a Canvas calibration tool. That allows you to see the canvas in the true size of the final output. If you are trying to make a Business card, then the tool will allow you to see that card during design at exactly the size it really will have once printed. That is a great asset given the fact that things often look great till you see that all the detail get’s lost on the stamp sized final print out. A guide how it works is available later in this post.
INSTALLATION is simple. Extract the file in the bcast.zip archive in to the plugin directory of your ZBrush installation. On my PC it looks like this:
If you do not have the directory, simply create it.
After the installation of the file, start ZBrush and the menu should be available under the Document Tab.
HOW TO USE THE PRINT SIZE BUTTON
You need a ruler. Metric or Inches. The calibration routine will ask for the measurement of 6 inches on your screen, metric people use 15.24cm instead.
The procedure is very easy. Start ZBrush, take the ruler, Zoom the canvas so it is 6 inches (15.24cm) wide. Then shift-click the Button and you are all set. Next time adjust the dpi slider to the desired setting, hit the ‘Print Size’ button and the canvas should snap to the right size on screen.
Now, if you are generally DPI challenged and have no idea what I was referring to with the term ‘ratio’. Then I invite you to follow my desperate attempt of shedding light onto those terms and associated issues…
If not, or you have better things to do than to worry about it, just use the preset’s and you will have distortion free prints.
Here is my guide for the DPI challenged, I hope it helps and it is not confusing anyone even more:
The illustration above seems to be trivial, but it is actually all you need to understand the entire topic. DPI is the abreviation for Dot Per Inch. One could also say pixel per inch. Depending on the device in use, the term varies.
The term DPI is used in a few and confusing ways. Let me try and clear those up.
A LCD screen is a good example of a ‘simple’ device from our current point of view. We know that it has a specific native device resolution. HUH?. That is the resolution the underlying technology of the screen is giving us as a maximum. I have two screens. One has 1600 dots Horizontal and 1200 Vertical. And the other 1280x1024. Where 1280x1024 is a dimensionless number. HUH??. 1280x1024 does not tell me anything else than the amount of pixels available to display something. The single pixel could be the size of an orange, which would make the size of my screen area 1600 Oranges wide and 1200 Oranges high (wooaaaa LARGE!!!), or the size of the pixel can be very very small, which could make my screen look very very crisp at the size of a postal stamp. So… how can I relay the size and the resolution more meaningful than 1600x1200. That’s where I use Dots/Inch or DPI to give someone the ability to understand what I am talking about. I can measure my screen. And the horizontal width is 17 Inches. Nice!. Now I know that I have 1600 Dots per 17 Inches. I could say 1600/17Inches. Not convenient. I use the following formula to arrive at the 1 Inch reference we all use: 1600 Dots divided by 17 Inches. That results in roughly 94 Dots Per Inch. 94DPI. That’s it?! Yes. But keep in mind, that this is the HORIZONTAL resolution. IF the dots are round, or perfectly square in the case of LCD’s, then this will also be the DPI for the vertical resolution. In case of my monitor that applies. Now you know how the screen resolution from 70-90DPI is coming together. The lower the DPI ratio is, the coarser the image will look, the higher the DPI ratio, the finer the display will look. A Screen with 300DPI would be nice wouldn’t it? Well, yes. After consideration of the HUGE amount of memory to drive such a screen and the massive performance your PC has to spend on the calculations for that massive bag of pixol’s you might be just happy with what you have right now.
Till we have a processor for every pixel, and I am sure that will be sooner than later, large displays are a computational pain in the neck.
A Device where this does not apply is the Printer. And mostly Scanners as well. Those devices have resolutions like 14400 DPI X 600 DPI, which could be a printer which can produce a high resolution horizontly in one stroke but not so much vertically as the printhead is not the size of your Microwave.
I refer to those DPI’s as the ‘native’ DPI because that is what the device can give you for REAL. That’s based on how many nozzles the ink head has, the amount of pixels in your LCD screen. Hard facts. Things you can verify with a magnifying glass. Now… How does that fit together with this plugin and the sizes.
I am not going to explain how a printer driver works. But, once you understand what the bcast plugin is based on, you will be able to guess yourself what that piece of software is doing.
For our example I chose the US Letter format wish is 8.5 Inches wide and 11 Inches Long. Now, my printer can print up to 600DPI (Laser printer, square pixel, so horizontal and vertical resolution are the same). That means I can print my graphics on that printer in any resolution UP TO 600 DPI. The printer manufacturer could also offer (and the cheaters do!) a non native 1200DPI mode! All they do is chop everything in half… We are not going there. We keep it real. Any case, we can see that there are 600 possible settings for the Letter button when it comes to the DPI adjustment. Does that make sense? No, not even a slider makes sense. Why? Because you might have another printer then I do. You might have a high res printer with different horizontal and vertical resolution. What then? So… what is the idea behind the bcast way of creating distortion free output?
Well, the ‘secret’ is in the RATIO. That is the relation ship between Horizontal and Vertical resolution. If I have a sheet of letter sized paper, and I take another LARGE piece of paper and make that 10 times as wide and ten times as long then the small piece of paper, then I can paint something onto the letter sized small paper, put it into a projector, project it onto the large paper, and TADA! the picture fit’s perfectly. I could also paint something onto the large piece of paper. Take a picture with a camera, project that slide onto the small letter sized piece of paper and again, the picture will fit nicely.
THAT is what bcast does. It creates a canvas size in the same RATIO than the selected output size. International Paper Sizes, have the square root of 2 as basis. So… in our case we only need ONE setting for all ISO paper sizes. TO make our plugin less boring the US Citicens with three feet and twelve fingers have developed a rather incoherent pile of paper formats leading to the heap of definitions in the plugin.
Back to the sample of the Letter Format for a final and quick explanation.
We have 8.5 inches width and 11 Inches length. The results in a 1/(8.5/11) ratio of 1.2941. This is a dimensionless number. So we can use it to scale anything else as well. Let’s try and get a Landscape representation of this onto our canvas. The maximum resolution we can have is 4096 dots in either direction. In case we go for high quality we go for the full 4096 resolution. In case we do not need this, there is an alternative 2048 dot mode which saves memory and responds quicker. This is an arbitrary number I have chosen. OK… back to the 4096. Landscape means it’s wider than high. he have to allocate 4096 pixols to the horizontal. So, the resolution would be 4096xWHAT??? Simple, 4096/RATIO is giving us the right value. That would be 3165 Pixel. An Image consisting out of 4096x3165 Pixel will have the same proportions then a 8.5InchX11Inch piece of paper. So, regardless of the DPI in the end, the Image can be scaled proportionally to the Letter size without distortion (enlarging one side more than the other). All other formats are guided by the same principle, the options set up the canvas accordingly and the output will look just great. The printer driver now takes on the roll of scaling your data so it fits nicely onto the output medium. It will add or remove pixels according to various (bicubic for example) algorithms during scaling so that the best quality can be achieved.
Now that’s really it. I hope it is of use for someone.