Build a 3D model in ZBrush from online reference in 15 min or less

NYC Street Manhole cover
Hello everyone this is Garry bringing you another quick asset modeling technique. (One of my favorite modeling tips)
First google or search out an image, or a few, of your subject matter. This works for small props and is super fast way of getting a detailed model from a photo to a 3D model “Quick”. Crop it and get it as straight as possible in photoshop.

Next use the magic want selection tool and select as much of the area you feel has contrast. Then paint all of it in with a bright color such as green to see what is and isn’t covered yet. Then paint by hand the areas you need to and erase the areas that will later be the holes and mid color of the man hole cover.

Next after you have all the upper areas filled in with the bright green change that color to a dark near black and we will call that the upper level.

Now we move to the mid level of detail. We need a mid level of gray and some of the specles and highlights in the reference can be smoothed out here to reduce the level of pitting. We want some small bump, but the reference at first caused me to go back to the photoshop file and give the speckle a little less contrast. This part will be different for each reference so keep pshop open and make quick tweeks for ease and speed.

Next add a little lighter near while color for the pitting and for the holes (if you have any) you can make that white. My image has asphalt in the areas that would normally show a bolt so I left this alone.

The outer ring has a little bevel that I wanted to quickly add from the reference so I selected just the outer ring and placed it above the top level using the “Lighten” at 44%. Now save this psd out to a folder so it will save the alpha channel as it appears above. Now its time to go to Zbrush. If you don’t already own zbrush go here and download it DUH!

Open Zbrush 4.6 and either find the alpha section at the top or if you have a custom layout open the Alpha section.

Under the Alpha tab select Import and browse to the psd file we just made and saved from reference.
Select the PSD file and it will come in to the Alpha window as a small icon.

In the Alpha tab use the Inverse button to flip the color of our image because as you can tell from my image above the background is filled in white.
No you see in the icon view it looks more correct for what we want. We need just the manhole cover to be a 3D model and we don’t want to have anything in the background.

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Next under the alpha tab still under Make 3D select a resolution of about 1024 in order to get the detail level to show what is in the image. Might need more or less and this will depend on your model and reference. Then set the Mdep at 15 which should be about the right thickness for the manhole cover. And turn the MsM down to 1 as we don’t want to smooth things up much untill we see what it will do. Lastly select the button named “Make 3D” and after processing the model will appear in the tools ready for you to drag on screen.
Here is a version of the model with a little more detail and pitting to the model using more of the texture the model came out with in the beginning.13variation
This version is a little smoother option I changed the photo shop file real quick and smoothed out the image by covering a lot more of the intital reference image on the lower layers.
Now this last image is using a shader I applied in Zbrush materials and AO from the BPR render settings. I set this up and moved the lighting just quickly for a quick render shot within Zbrush to see how the models looking. Please note my workflow would probably go further and take this on out to Maya next and place it in a scene to render. Or possibly decimate the model a little to make a lower poly version to go out to Maya then Cry engine. But those are tutorials for another day.


I hope you enjoyed this one and will stay tuned in to see more tutorials as I load them. Please drop me a note if you have questions or would like to see something in a tutorial. I’ll try and work it in.