I know that a lot of people have come into these forums looking for info on how to get their high-rez, polypainted models exported for 3D Printing, myself included. There is very little in the way of a how-to so I am writing this to show proof of concept and leave it up to you to take further for your needs. I have successfully achieved this with ‘reasonably’ high-rez models and yet time and again I run into problems. And now with the release of 4R7 my workflow again did not work as before! I have corrected this as you will see below.
This tutorial uses one painted low-rez subtool exported which is then uploaded to Shapeways.com for printing. Some people will be satisfied with low-rez painted models, but as 3D Printing technology gets better and better, we as artists are going to want something better in terms of sharpness and definition. The question you will have to resolve for yourself, then, is how to get that beautiful 10mil polypainted model down to a decent size for printing. Anyone who hasn’t tried this is now immediately thinking “easy - just decimate and project”… Nah, it ain’t that easy!
So here we go then. I’ve just been through this myself working on it for half the day, so I hope I don’t mess up any of the steps (I’ve tried so many things today!).
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Create a low rez cube Cube3D. Go into Edit Mode, of course, and now Make Polymesh3D. Should be about 512 polys, if I remember right.
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For poly-painting I like to work with a white surface so click on Material and choose SkinShade4.
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Click on Color at the top menu and hit FillObject button. Nothing seemingly happens but it has.
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Because 512 polys is a bit TOO low for painting any sort of detail on, go into your Geometry tab and hit Divide three times taking the subtool to sub-d 4 and about 31,000 polys.
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In your toolbar at the top turn Zadd OFF and make sure RGB is ON (100% intensity if you want intense color).
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Now pick any colour(s) you want and paint on the model. Don’t make anything fancy because if this doesn’t work for you then you won’t have wasted a lot of time. But DO make sure whatever you paint will be identifiable when viewed after export as having been successfully translated. In other words don’t paint a big red circle in the middle of one of the faces because even if the texture file gets rotated it’s still gonna look fine! Perhaps draw some numbers on each of the faces.
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In the Geometry tab delete all lower sub-divisions of the model or the next part won’t work.
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Here’s where it gets a bit mystifying for newcomers to ZBrush… We need to get some UV’s onto our model so that we can create a texture to export with our model…So, click on Zplugin at the top and choose UVMaster.
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In UVMaster leave defaults as they are and simply hit Unwrap. With this low-poly model it should only take a few seconds to do its job, depending on your machine, but with a very high-rez model you may as well have a look out your window waiting for the cows to come home.
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On we go… In the right hand trays open up the Texture Map tray. Click on Create and then Create from Polypaint.
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You should have seen the texture pop up in the tray after the above. Now click on Clone Txtr button to the right of the texture icon.
12 Now the texture has popped into the texture icon above your Material icon. Once again we go to Zplugin and this time choose 3D Print Exporter. Yes, the tension is palpable, isn’t it?! -
First of all hit Advance Options near the bottom of the palette. Choose PNG (not JPG as I’ll explain later) and uncheck Colors (not really necessary but it will stop your system producing an unnecesary file). All other defaults should remain as provided (I’ll discuss the sizing section later). Now click on the VRML button to start the export.
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Select the directory where the files will go and supply a name.
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Minimize ZBrush but don’t close it yet; I want you to have a look at that texture file orientation later.
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Navigate to the directory where you saved those files. You should see two files named “your file.wrl” and “your fileTex1.png”
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Now, here’s the bull**** part that was vexing (polite word) me for the longest time today. Compare that PNG file with the icon in ZBrush. They ain’t oriented the same are they? So, you say to yourself, simple, all I have to do is rotate the image to look like it does in ZB. Um, no. You need to open your photo editing programme and flip that two rotations clockwise, or 180 degrees total. So now it looks like the one in ZB but flipped left to right. Yeah, you got it, made total sense to me, too! Make sure you save the file with the exact same name or you’ve just made love to yourself again.
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Now, I’m using Win 8.1 on a PC so the next part is a piece of cake. You need to create a zipped file with those two files in them however you normally do it. For me it’s a matter of selecting the two files, clicking on Share and then the Zip icon. Done. That’s it, you’re finished. Sort of.
Now what? Well, for me the next part is uploading the file to Shapeways.com. I won’t bore you with the details here. Just remember, if you used the “Inches” scale in 3D Print Exporter you should choose that scale on upload.
Which now segues me into scaling in ZBrush. This is a whole other issue that has been covered many times. Basically, though, if you have a model loaded - a character let’s say, and you want to print that out at 5 inches in height. Find out which axis the height of your model is on, go into 3D Print Exporter and on that axis type 5 and then tab. The other axes will scale automatically. Do NOT hit Update Size Ratios once you’ve reached part 13. In fact, I don’t click it all. Make sure any sizing is done BEFORE item 8.
Now, regarding that note I made about choosing the PNG format and not JPG earlier. ZBrush saves the file with the extension JPEG (or at least it did prior to 4R7) and when uploading to Shapeways this is not recognised - their system looks for JPG. Yep, another crappy part about all this that took me ages to figure out.
Despite what I said at the beginning, I did in fact walk through this step by step as I wrote it so I know it works.
If you have any questions by all means ask. I certainly ain’t no expert but I’ll do my best to help.
There are very many talented people here who for some reason or other haven’t (at least I can’t find it) explained the easiest way to get a high-rez poly-painted model exported for PRINTING with beautiful textures UV-mapped. Please, please correct me if I’m wrong, but make sure it works because I’ve already been through the “Hey, why don’t I try this?” stage a great many times.
Good luck and happy modeling.
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