Reference images can help you reverse engineer a product or simply get a great starting point for the overall shape of a product. I often find myself using reference images when sculpting objects, as it helps you turn that initial sculpted box into a more defined shape.
Here are the two reference images that I used in this tutorial. Click the “Download Image” button to download each image.
Common Sculpting Errors
While using Fusion 360’s Sculpt environment you’re bound to run into the self-intersecting error. When you go to hit “Finish Form” in the toolbar Fusion 360 will prompt the error message “T-spline self intersects body” and it will not let you turn the sculpted body into a solid body.
Check out this help article to learn some common troubleshooting techniques to fix this error.
Edit Form Icons Explained
More Sculpting Content
By the end of this video, you’ll know how to sculpt a bike seat in Fusion 360’s Sculpt environment.
To start, we’ll want to insert two reference images of a bike seat, which will help us define the overall shape. You can download the reference images at ProductDesignOnline.com/11… that’s ProductDesignOnline.com/11.
Once you have the reference images downloaded we’ll need to select the “insert” dropdown menu. Then, we’ll need to select the “canvas” option from the dropdown list or you can select it in the toolbar.
Within the canvas dialog box, I’ll select the image selector, which opens up my computer’s files folder. From here, I’ll select the image of the top profile of the bike seat. Then, I’m going to select the XY origin plane for the face to place this image on.
We’ll make the image the correct size in just a minute, but for now, I’m going to simply drag the corner scaling icon to make the image larger. Then, I’ll click the “OK” button in the Canvas dialog box to confirm the results.
To insert the side profile image we can right-click to select the “repeat canvas” option. This time I’ll select the XZ plane. I’ll select the image selector. Then, I’ll select the side profile image and once again I’ll drag the corner scaling icon to increase the size of this image until it’s approximately the same size as the other.
Before clicking the “OK” button I’ll select the “Horizontal Flip” option to ensure that the front of the bike seat is on the righthand side. Then, I’ll click “OK” to confirm the results.
Now that we have both reference images in place, we can calibrate them to their correct size.
I’m going to first toggle open the canvases folder in the Fusion 360 browser.
To calibrate an image you’ll need to right-click on the image in the Fusion 360 browser and then select “Calibrate”. After selecting calibrate for the top view, I’ll select the top of the view cube so I’m looking directly at it.
To calibrate the image we’ll need to define two points and then we can define the distance between the two points. I’ll simply click on the left edge of the image. Then, I’ll click on the right edge of the image.
The length of this bike seat is 277mm, so I’ll type that out within the input box. Pay close attention to what happens as I hit the enter key on my keyboard.
You’ll see that as you hit the enter key the image is scaled to your desired size.
We’ll now need to calibrate the second reference image. I’ll right-click on the side profile in the browser and I’ll select calibrate. This time I’ll select the “front” view of the viewcube to look directly at it.
Once again I’ll select the left side of the image and the right side of the image. Then, I’ll type out 277mm before clicking the enter key on my keyboard.
Now that we have our reference images set up, were ready to enter the Sculpt environment.
If you select the Workspace dropdown list in the upper lefthand corner then you’ll see that “Sculpt” is not one of the available options. That’s because the Sculpt environment is an extension of the model workspace, which is why its referred to as an “environment” and not a “workspace.”
The only way to enter the Sculpt environment is to select the purple “Create Form” cube in the toolbar or from the create dropdown list.
We’re going to now start by creating a sculpted box. I’ll select the “Box” option in the toolbar or from the “create” dropdown list. Then, I’ll select the “home” icon next to the viewcube to view this model from its home position. This simply makes it easier for us to see all the origin planes.
We’ll want to create our box from the center origin because our reference images are centered with the center origin point.
I’ll click on the XY origin plane and then I’ll select the center origin point. As I drag out with my mouse you’ll see that we can enter dimensions for the box. I’ll type out 277mm for the length, so it matches the length of our reference image. Then, I’ll hit the tab key to lock that dimension in place. This will also switch the cursor to the other input field where we can type out the width. I’ll type out 140mm for the width.
This is where you’ll have to be careful not to hit the enter key. We just want to hit the tab key once again to lock the width dimension in place and then we’ll move the mouse cursor around.
This will let us edit the box details before we finish creating the box. If we had hit the enter key it would create the box as we currently see it.
Looking at the box dialog, you’ll see there are several options that we can define. We’ve already defined the length so let’s look at the second option, which is the number of “Length Faces”.
In general, when creating sculpted forms, I always recommend starting with fewer faces as it’s always easier to create more faces rather than delete or merge faces. With that said, we just want the right amount of faces to be able to control this box shape to reshape it to the bike seat, so I’ll change this to 6.
Next, you’ll see the width that we already defined…so once again we can define the number of faces but this time for the width. I’ll type out 4 for the number of faces… and you can be anywhere between 3 to 8 faces here… I would just recommend not doing more than 10 faces.
Before changing the height, which is the next setting, let’s take a look at the direction option which is just below it. If we look at the box, it currently extrudes towards the top. Our reference image is centered so we’ll want to change the direction type to the “symmetric” option, that way our thickness lines up with the reference images.
If we look at the “front” face of the viewcube, we can drag the single directional arrow down until the box appears to line up with the reference images. You’ll see we need a height of about 60mm. I’ll also set the number of height faces to 3, as we won’t be changing as much in this orientation.
The last option that we need to look at is the symmetry option. Fortunately for us, a bike seat is symmetrical, which means we’ll be able to focus on one half of the design while the other half can simply be mirrored. To do this, we’ll want to set up a symmetry line down the middle of the bike seat.
I’ll select the symmetry dropdown selector and I’ll choose the mirror option. Then, I’ll select the “Width Symmetry” option, which creates a green symmetry line running down the width of the box, or in our case, the length of the bike seat. We can now select the “OK” button to create this box.
Now that our box is created, let’s take a look at what happens when we select one of the faces. You’ll notice that the corresponding face is highlighted in yellow on the other side since we have the symmetry option set up. Again, this will let us focus on one side of the seat, while the other side is updated accordingly.
Whenever I’m sculpting an object to reference images, such as this bike seat, I like to change the opacity of the body. I’ll toggle open the bodies folder and then I’ll right-click on the sculpted body. I’ll then select the “Opacity Control” flyout folder, which is at the bottom of the list. I usually like to select 50 or 60%.
After selecting 60% you’ll see it’s now easier to see the reference images while still being able to see the faces and edges of our sculpted body.
Now that we’ve done the groundwork, we’re ready to sculpt the body of our bike seat. I’ll select the top face of the viewcube to look at the top of the seat. You’ll also want to select the viewcube menu dropdown and make sure that you have yours set to “orthographic”. If yours is set to “perspective” then some of the sculpt edges may appear to divert from their true orientation.
If you want to become proficient in the Sculpt environment then you will have to spend a fair amount of time practicing. I can’t stress this enough. I often get people messaging me or commenting that the Sculpt environment is so hard in comparison to the model Workspace… but it ultimately comes down to practice and understanding that it is a different type of modeling which requires a different approach.
The first thing I’m going to do is shrink down the front part of the bike seat where it’s narrow. I’ll look at the model from the home position.
Then, to start, I’m going to hold down the shift key and I’ll select the front 6 faces of the cube… and the other 6 faces will be highlighted or selected on the other side.
Then, I’ll right-click to select the “edit form” option. If you haven’t already then I suggest you watch my video on the edit form icons, as I won’t be covering each icon in this tutorial. For your convenience, I’ve put that video on this tutorial’s resource page.
I’m going to select the top view of the viewcube and then I’ll take the “Single Direction Scaling Icon” and I’m going to drag that down as much as it will let me. You’ll see that the front of the bike seat is starting to shrink to its normal size.
To shrink it even more, I’ll select the “Planar Direction Icon” or the rounded square and then I’ll drag that in towards the middle. Take notice of how convenient it is just worrying about altering one side as our other side is updating because we turned on the symmetry option.
Next, we’ll want to start by shrinking down all of these edges or dividing lines. We’ll want to select them all the way around so we’re scaling the entire object. To do so, you’ll need to double-click on the edge, which as you’ll see will highlight the entire edge in blue.
Then, I’ll drag the “Single Direction Scaling Icon” towards the center to resize the width…and this is were sculpting starts to become very different from parametric modeling. It requires a lot of fine tweaking and back and forth.
I’m going to repeat these steps to the next few edge lines while also going back and forth to tweak them until I get them closely aligned with the reference image. I’m also not going to worry about the very front of the seat at this point, as we’ll finetune that later.
Once I get to this fifth edge you’ll see that it doesn’t work with the curvature of the bike seat. This is where we’ll need to subdivide faces or we’ll need to insert more edges to get proper control over the shape.
To subdivide this area I’m going to want to select all the faces all the way around this box. I’ll select one face, hold down the shift key, and then I’ll double click on the face next to it. You’ll see that selects the entire row in a similar manner to how I select entire edges.
I can now select the “modify” dropdown list and I’ll select the “subdivide option. This will let us split these faces into half, in other words, subdividing them. However, you’ll see that we have some options to choose from. If we select the “exact” option it will try to subdivide the faces while keeping the original shape intact. We’ll also want to select “specify” to choose the number of faces that we’re creating. I don’t need any extra faces in the length direction so I’ll set this to number to 1. For the width we need to split it in half so I’ll enter number 2. Then, I’ll click “OK” in the subdivide dialog box.
We can now double-click on the edge line to select it all the way around. Then, we can select the edit form icon in the toolbar.
Now we can adjust both of these edges using the “Single Direction Scaling Icon”. After I spend a few seconds tweaking each edge line, you’ll see that I’m able to get them to better match the overall shape of the bike seat, as I now have more control over the faces.
It also appears that we’re going to need to do this once again for the next section. I’ll select a face and then I’ll double-click on the face next to it while holding down the shift key. Once the entire row is selected I’ll select “subdivide” from the modify dropdown menu. Then, I’ll use the same settings, which the dialog box defaults to, so I’ll click “OK”.
I’ll double-click on the edge again and I’ll select edit form in the toolbar…and I’ll just rescale both of these edge lines until they’re aligned with the bike image.
Now that we’ve fine-tuned the center section of the bike seat, let’s take a closer look at the front. I’m going to hit the home icon next to the viewcube and then I’ll zoom in a bit so it’s easier to see.
The tricky thing with the front is that we need this to be rounded over, but if we have too many faces then we’ll end up with this boxy shape. I’m going to first close out of the edit form command.
What I’m going to do is hold down the shift key and then I’ll select the three edge lines that divide the front faces. Then, I’ll simply hit the “delete” key on my keyboard to delete the edges.
After they’re deleted I’m going to hold down the “Shift” key and I’ll select all 6 of the front faces on one side of the symmetry line. I’ll hit the edit form icon in the toolbar. Then, I’ll look at this from the top view.
I’m going to first drag the “Single Direction Scaling Icon” inward…until these faces start to come in and become more rounded over. Then, I’m going to drag the “Planer Direction Icon,” or the rounded square, and I’ll drag that to the left until that front shape starts to better represent the reference image. You may even find that you need to jump back and forth between the tools to fine-tune this shape.
Now that I’m happy with the overall shape, you’ll see that I lost a little bit of our length of the seat by bringing it back. You’ll find that as you work with sculpted objects it’s a lot of back and forth as any time you’re moving faces or edges you’re affecting the ones around it as well.
I’m going to select all three rows of the faces at the front.
Once I have them all selected I’ll drag the “Planar Direction Icon” towards the right and I’ll finetune this until it aligns with the reference image.
The front of our bike seat now looks a lot better so let’s spend some time working on the back of the seat. Before doing anything, I’ll be sure to click “OK” in the edit form dialog box to confirm the recent changes.
Then, to work on the back I’m going to spin the model around using the orbit tool.
I’ll hold down the shift key and I’ll select the 5 edges that make up the corner. I’m going to hit the delete key to delete the edges making these corner faces a bit larger, which also makes altering the faces easier to work with.
Now, I’ll hold down the shift key again and I’ll select the 5 corner faces. I’ll select “edit form” in the toolbar. Then, I’ll look at the model from the top view.
I’m just going to drag that “Planar Direction Icon” around until this lines up with the edge of the bike seat…and you’ll see that lines up pretty well without too much modification. Be sure to click the “OK” button to commit your edit form changes.
To finish off the back of the seat we’ll need to create this back curved area. I’m going to look at the back of the seat and while holding down the shift key I’ll select the edges lines that are directly in the centerline of this seat.
I’ll hit the “edit form” icon in the toolbar. Then, I’ll make sure to look at this from the top view. At this point, we can drag the single directional arrow towards the right. You’ll see at about 40mm that I’m able to recreate the same contour shape…we’ll just need to stretch the seat back out to its full length.
I’m going to select the back three center faces while holding down the shift key. I’ll look at the top view again. Then, I’ll drag the rounded square or the “Planar Direction Icon” towards the back and inwards just a bit to position this where everything lines up with the reference image. Once again, I’ll be sure to click “OK” in the edit form dialog box to confirm the changes.
Up until this point, we’ve been focusing on the top profile of the bike seat. We’ll now want to head to the side profile where we can adjust the thickness of the bike seat.
I’m going to start by selecting the 6 faces that make up the front tip of the bike seat.
Once they’re all selected I’ll look at this from the front side of the viewcube and I’ll select “edit form.”
I’ll then drag the single directional scaling icon to shrink this down. Then, I’ll drag the planar direction icon and I’ll move that up to narrow the front portion of the seat.
Next, I’m going to select a face on the next row and I’ll click the shift key and double click to select the entire row. I’m going to then drag the “Planar Direction Icon” upwards…and then I’ll drag the “Single Direction Scaling Icon.”
I’m going to now repeat these steps for the next three or four rows of faces. Similar to before, I’ll bounce back and forth between the “Single Direction Scaling Icon” and the “Planar Direction Icon” to move and scale these rows until I’m happy with their overall shape.
I should also reiterate that the reference image is there to give us a good idea of the bike shape, but we don’t need to match it completely. Once we get the overall shape done then we can tweak the sculpted body to our desired needs or we can modify it further in the model workspace.
I’m going to hit the “OK” button to close out of the edit form dialog, as we’ll need to delete some back faces to reshape this back.
Remember, that you can always turn the opacity back up to 100% if you’re having trouble seeing the faces and edges.
As I begin to work on this backside of the profile I’m also considering how the seat will be in terms of thickness. The next steps will be to delete some of the bottom faces, as that’s where the structural support can be added in the model workspace.
One approach to this backside would be to select a bunch of faces and then delete them. We can then rearrange the points of the edges.
I’m going to hit the number 3 key on my keyboard to switch to the “Paint Selection” or you can select “Paint Selection” in the select dropdown list.
Then, I’ll simply drag my mouse cursor or “paint” over the faces in the lower-left corner. After I select all of the faces that follow the angle of the back seat I’m going to hit the “delete” key on my keyboard.
If I now look at the back of the model, you’ll see we have a hole in the seat, which is okay as we wanted to open up the bottom side of the seat. I’m going to fine-tune this backside a bit by selecting one of the points and then I’ll hit the “edit form” icon in the toolbar.
I’m going to look at the model from the “Front” view and then I’ll drag the “Planar Direction Icon” around until the point moves the contour in place.
I’ll continue to click points and drag the rounded square around to reposition and shape the backside. Once again, this just takes a little bit of back and forth to get right until you’re happy with the overall shape.
If I now take a look at it, you’ll see there may be some weird curvature of on the underside. I can select those points as well and move them around…and I may have to look at the bottom side of the viewcube to get this to work. Lastly, I’ll be sure to click “OK” to confirm the “Edit Form” changes.
After I’ve spent some time cleaning up the back edges, I’m going to look at the bottom of the seat. This time, I’ll hit the number 1 key to switch back to the normal selection and then I’ll hold down the shift key and I’ll select all of the bottom faces. I’m going to then hit the delete key to delete the faces, opening up the entire bottom face of the seat.
Before we thicken these faces, we can make some more tweaks or adjustments to the overall curvature.
I’m also going to hide the reference images by selecting the “Canvases” lightbulb in the Fusion 360 browser.
I’m going to then hold down the shift key and select some of the top middle edges, where the green symmetry line is. I’ll edit form…and I’m going to drag the single directional arrow down to give this a small divot in the middle. If you’re ever dragging the arrows and they snap in at large distances then you can always type out smaller dimensions in the input field. For example, I may type out -7mm to see what that looks like.
I may even play around with the bottom contour of the back. I could select some of these back edges and then drag them in a bit with the single directional arrow.
Ultimately, working in the Sculpt environment takes a lot of time, patience and fine-tuning.
I’m going to look around to see if there are any other adjustments I may make.
For example, I could consider increasing the pitch of the back rounded edges.
Finally, once you have the overall shape to a good point where you’re satisfied, then you’ll want to add thickness to the seat body.
I’ll select the “modify” dropdown list and then I’ll select the “Thicken” command near the bottom third of the list. Then, I’ll select the bike seat body as the body to thicken.
You’ll see that we first have to type out the thickness dimension. I’ll type out 3mm. Next, we can choose the thickness type, I’ll want the edges to have a nice smooth round-over, so I’ll choose the “soft” option. Lastly, I’ll click “OK” to confirm the results.
Taking a look at this model…overall, it looks pretty good for just 30 minutes of sculpting work. The bottom sides could potentially use some further fine-tuning and additional design details could be added to the seat.
To take this back into the modeling workspace, simply click the “Finish Form” button in the toolbar. Then, you’ll be able to use the modeling tools to add the support structure and other parametric details.
If you do happen to get an error message about the faces converging then be sure to check out my other video where I demo how to resolve these types of t-spline errors. I’ve also put that video on this tutorial’s resource page.
If you made it to the end of this video then let me and the community know by commenting below if you would like to see more sculpting tutorials. If you do, then help me out by commenting the name of an object that could be sculpted.
Last but not least, I wanna give a shoutout to this week’s Patrons and supporters that joined us in the Product Design Online community. Thanks to Makerbarn_John and Ryan Lockwood for supporting all the Fusion 360 content that I make.
As always, I truly appreciate you taking the time to watch this tutorial. If you enjoyed this tutorial please click that thumbs up icon and click on that video in the lower right-hand corner to watch more sculpting tutorials.
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