Introduction: Digital Sculpting Hans Arp's L'Etoile in Zbrush and Fusion 360

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About: I'm a sculptor that mostly carves stone but sometimes makes 3D printed sculptures. I'm somewhere between student and professional.

Hans Arp is one of my favorites sculptors. He was an abstract artist and Dadaist. I chose L'Etoile because of it's simplicity and beauty of the form. In case you were wondering, L'Etoile is French for star. This guide will show the process that I used to start a sculpt using a reference image in Zbrush. The sculpt is then exported as a quad mesh into Fusion 360. That imported mesh is then converted into T-Splines for further refinement, materials are added, and finally how to render. You can make nice renders in Fusion 360 easily.

Supplies

  • A computer and a mouse with a click wheel
  • Zbrush
  • Fusion 360
  • Reference image

Step 1: Loading the Reference Image Into Zbrush

I did an image search for Hans Arp L'Etoile and chose one from Christies Auction House.

Load your reference image into Spotlight. Spotlight is a projection texturing system in Zbrush.

  • Texture -> Import
  • Select the image that you just imported and click Add to Spotlight button.
  • Use the Spotlight tool to adjust the opacity and scale the body of the sculpture to fit the screen.
  • Click the Z key on your keyboard to drop the image to the canvas.

Step 2: Create the Donut Shape for the Main Sculpture Body

  • Tool -> SimpleBrush -> Ring3D
  • Click and drag the ring onto the canvas.
  • Click the Edit button to enter into Edit Mode.
  • Make sure direction head is facing forward.
  • Click the Z key to unhide Spotlight and adjust the opacity to your liking.
  • Click the Z key again to hide the Spotlight tool.
  • Initialize -> Align Z Tool -> Initialize PolyMesh3D
  • Click the Scale button and resize and move the donut with the Gizmo to be the thickness of an area of the sculpture, I chose the upper right hand area, see image.
  • Center the donut over the hole in the sculpture with the Gizmo.
  • Click the Draw button to get back into sculpting mode.

Activate symmetry in the Z axis. This will let us work on both sides of the donut at the same time so we won't get a lopsided form later.

  • Transform -> Activate Symmetry, Click Z Symmetry button.

Step 3: Starting the Sculpt

  • Click the B key on the keyboard to bring up the Brush Palette. Then click M, then T. This selects the Move Topological brush.
  • Use the S key to resize the brush, set to something like 400.
  • Select an area close to the inner part of the donut and drag to match the inner curves of the sculpture. Make the brush size smaller to move smaller areas of the donut.

Step 4: Time to Dynamesh

Dynamesh will make the donut act more like clay and make it easier to create the rest of the form.

  • Tool -> Geometry -> Dynamesh Set resolution to 32, click the Dynamesh button.
  • Continue moving the mesh around and resize the brush as needed. Be sure to retopologize often by holding down the CTRL key and drag on an empty area of the canvas. This will fix the mesh when it starts to look stretched out. When you get to the points of the sculpture, you can set the Dynamesh resolution to 64 to give you more geometry to work with. When you are satisfied with the form, click the Dynamesh button again to toggle it off.

Step 5: Remesh With ZRemesher

  • Shift + Z to hide the reference image for now.

The mesh is bumpy looking but we will fix that.

  • Tool -> Geometry -> ZRemesher

Make sure the Adapt button is clicked.

  • Click ZRemesher button.
  • In the ZRemesher sub-pallette click the Half button.
  • Click the ZRemesh button.
  • Keep on clicking the ZRemesh button to lower the resolution to the point that the form still exists. In my case around 985 ActivePoints. If you go to far then just undo until it looks ok.

Smooth the mesh with polish

  • Tool -> Geometry -> Deformation -> Polish
  • Slide the Polish slider to the right about 6 then let go. This should get the bumps out.
  • Bring back the reference image with Shift + Z and realign your sculpt over the reference image.
  • Do some slight adjustments to the mesh with the Move Topological Brush to make it more like the reference image since it shrunk and moved a bit from the polishing.

Step 6: Making the Base

  • Click Z to open up the Spotlight controls and slide the reference image up so that the base is shown. Don't make any changes to the reference image. Hit Z again to hide the controls.

Add a cylinder for the base.

  • Subtool -> Insert -> Cylinder3D

In the Subtool Palette, click on the eyeball next to the sculpture to hide it. While we are over here, lets rename our subtools.

  • Click on the sculpture subtool, find the rename button below and click it, rename it Sculpture and hit enter. Do the same for the base and rename it Base.
  • Use the Gizmo to resize and move the base to match the reference image.
  • Shift + Z to hide the reference image.
  • Click the eyeball next to the sculpture layer to make it visible again.
  • Use the Gizmo to move the base below the sculpture so it looks like its sitting on top of it. Turn the view to the side and check the alignment from that angle to make sure the sculpture is in the middle of the base.
  • Now is a good time to save the file. File -> Save As and save it.

Step 7: Exporting the Meshes

  • Go to the Subtool Palette and click the eyeball next to the Base to hide it.
  • Make sure the Sculpture is selected in the Subtool Palette.
  • Tool -> Export Save it as an obj file.
  • Repeat for the Base.

Summing up this part.
The sculpture and base were sculpted in Zbrush from a reference image. Then the sculpture was Zremeshed to make it into a low poly quad mesh. Then the sculpture and the base were exported as .obj files.

Step 8: Fire Up Fusion 360

Importing the quad meshes.

  • Preferences -> Mesh
  • Make sure Triangulate mesh polygons is unchecked. Click OK to close. (important for later steps)
  • Right click on Document Settings and Select Do not capture Design History. Click Continue in the Warning window. This will activate the MESH workspace.
  • Click on the MESH menu to get into the MESH workspace.
  • CREATE -> Insert Mesh (select Sculpture.obj) Click open, click OK in the next window. Repeat for the base.
  • Rename the imported meshes. Fusion 360 gave our meshes weird names. Click the sculpture mesh and under the Bodies section double click the highlighted name and call it Sculpture mesh. Rename the base as Base mesh.
  • Before we forget lets save our work.

Step 9: Scaling the Meshes to Real World Size

According to the auction site that sold the original, the sculpture and base is 25 inches (635mm) tall.
So lets measure this and see what we have.

  • INSPECT -> MEASURE

I put a point at the top of the sculpture and at the bottom of the base. It gives a reading of 33.527 mm. Its a sculpture for Ants now, we'll need to scale this up so it's life size. Close the MEASURE window.

Lets scale this up.

  • MODIFY -> SCALE

Select the sculpture and base, Scale Type is Uniform. We'll do a scale factor of 19. I just divided 635 by 33.527 and rounded up to get that number. Click OK to close the window.

Let's measure again to see what we got. I got 635.596, good enough for government work, so on to the next step.

Step 10: Convert Meshes Into T-Splines

  • Click the FORM menu to get into the FORM workspace.

Convert the quad mesh into T-Splines.

  • UTILITIES -> CONVERT -> Convert Type: Quad MESH to T-Splines, select both meshes, Operation: New Body, click OK to close this window.

You now have some beautiful smooth forms. You can further refine the forms using operations under the MODIFY menu if it pleases you. Lets rename our new T-Splines sculpture to Sculpture T-Splines and the base to Base T-Splines.

Whoa that's not what we want with the base but it can be fixed.

  • Hide the Sculpture T-Splines by clicking the eyeball next to it.
  • Switch the display mode to Box Display. Alt + 1 This will make it easier to select the outer loops.
  • Select all of the top and bottom loops of the cylinder by double clicking on a segment to select the whole loop, while holding shift do the same to the bottom.

Now we will crease the edges to get the look we want.

  • MODIFY -> CREASE -> OK
  • Alt + 3 to get back to Smooth display.

Now the top and bottom of the base are perfectly flat.

Step 11: Rendering

  • Unhide Sculpture T-Splines by clicking the eyeball.
  • Switch to the RENDER workspace.

Apply a material to the T-Splines

  • SETUP RENDER -> SETUP -> Physical Material

I'm going to go for a polished bronze look for this one. So go the the Metal folder and scroll down and find Bronze.

  • Drag Bronze onto the Sculpture T-Splines and Base T-Splines Close that window.

Setting up the Scene.

  • Render -> SCENE SETTINGS

I like to start with the Aspect Ratio, it's toward the bottom of the window. For this one we'll go with 1:1 Square. I find that selecting the Aspect Ratio will help with composition later.

The next thing I do is select an Environment.

  • Click the tab Environment Library. Choose one of the environments by dragging it onto the background of the canvas. For this I'm going to use an HDR that I found, you can load your own using the Replace Custom Environment at the bottom of the window.
  • Go back to the Settings tab.

I'm going to go for a Solid Color for the Background. You can change the color by clicking on the color patch next to Color.

  • Drag the color picker around and Apply to see it on your background. Find a color you like then OK.

Now is a good time to position the sculpture by moving it around and turning it. Next we will change the direction of the light. Click the icon next to Position.

  • Move the rotation slider around to find an angle that you like. Click on the Position icon to hide it.

The rest of the steps are a matter of taste so adjust the Focal Length and Exposure as you see fit.

  • Close the Scene Settings window.

Now we are on the last leg of this journey and ready to render.

  • Click the teapot icon RENDER to get to the RENDER SETTINGS. I'm leaving all of the presets for this but feel free to change things as you see fit. I'm going to render with Local Renderer and Final(75) for the quality since it's pretty quick on my computer.
  • Next hit Render and wait. If your render came out too light or dark go back and change the Exposure.

After your render is finished you can open it up by clicking on it in the RENDERING GALLERY. If you like how it came out you can download it to your computer. Feel free to try other materials and other environments.

Sculpting Challenge

Participated in the
Sculpting Challenge