Correcting the Model
There are a few issues with the model that need to be corrected; we walk through them here.
You’ll notice that the top of the surface on which your object was sitting may also be included in the model. Shortly, we’ll go through the steps to trim that off, leaving only the desired object behind as your 3D model.
After saving the model to your Autodesk account, you then can manipulate it further using the other Autodesk applications. We cover these in later chapters. Your model should appear in the Captures tab of 123D Catch on the iPad and in the My Projects section online after you log in to 123D Catch (see Figure 4.6).
FIGURE 4.6 Reviewing the finished output 3D model of the cactus in the online version of 123D Catch.
As mentioned, the bottom of the model contains the surface on which the object was sitting when you captured the images. We’re going to use the Plane Cut tool to trim off the bottom of the model, leaving behind only the cactus object, as shown in Figure 4.7.
FIGURE 4.7 Plane Cut tool.
Select the Plane Cut tool from the toolbar. A set of controls should appear on your model with an arrow pointing along the Z axis. The bottom of this arrow represents the bottom of the model and direction the cut will occur. A circular control on both the X and Y axis lets you rotate the cutting surface and align it with the bottom of your model.
In Figure 4.8, the arrow is pointing down. It should be pointing up; otherwise the top of the cactus would get cut off. Click and drag your mouse on either the X or Y circle (below the purple line in Figure 4.8) to rotate the cut line. It should snap at the 45o and 90o positions to help with alignment.
FIGURE 4.8 Ensure the arrow is pointing in the correct direction of the desired cut.
When the arrow is orientated correctly, you can then click and drag it to move the cutting plane up and down your model (see Figure 4.9). In this example, you want to see only the purple line along the bottom of the cactus which means that the cut will discard the countertop surface.
FIGURE 4.9 Moving the cutting plane.
Use the X- and Y-axis circles again to pivot the model along the plane until it’s level. The purple line represents the new bottom of the model. Press the Apply button when you’re happy with the position of the purple cutting line.
In Figure 4.10, you can see that the bottom of the model has been cut and the countertop surface has been removed from the model.
FIGURE 4.10 Cutting complete.
Orienting the Model
One last thing that you might need to do is orient the model so that it is upright for printing. You’ll notice in Figure 4.11 that in the upper-right corner of the screen the orientation box is upside-down.
FIGURE 4.11 Orienting the model.
To correct this, press the Orientate button from the menu; a blue plane appears on the model. Clicking the arrow enables you to rotate the model and correct the orientation (see Figure 4.12). In this example you need to rotate the model 180o.
FIGURE 4.12 Model orientated correctly.
Note that the upper-right box is now upright. You’ll need to save the model before you proceed to the next and final steps of repairing the model.
Repairing the Model
It’s not uncommon for scans to result in some holes or rough spots due to the software misinterpreting your source photos. This can be caused by a number of reasons, but usually it’s due to areas of the source object being in shadow or too similar to surrounding areas.
Fortunately, 123D Catch has some repair options included that will analyze the finished model. You can manually do some spot repairs to the model using the Smooth tool for rough areas and holes. Automatic repairs can be done using the Heal Mesh and Auto-Cleanup tools from the menu.
The Smooth tool is used to smooth out any rough points in the model that might not have been processed as accurately as desired. You can adjust the brush size using the slider on the bottom as well as the strength of the effect.
Start with small brush Size and low Strength; then work your way up (see Figure 4.13). You don’t want to apply too strong of an effect because it will look obvious on the model. Also, be sure you rotate around the model to smooth all sides of the model.
FIGURE 4.13 Smoothing the model.
The Heal Mesh tool detects any holes in the model and repairs them. Inspect the model after applying this to ensure it doesn’t close openings that you intended to be open (see Figure 4.14).
FIGURE 4.14 Getting ready to 3D print the model.
The Auto-Cleanup option magically fixes the model and removes any of the detached parts of the object. This is the last step you should apply. Again, inspect the model from all sides to ensure it didn’t over-repair any parts of the model unnecessarily. Use the Undo option if you aren’t happy with the results.
Finally, you can choose to preview the model for your 3D printer software or send it to a printing service (see Figure 4.15).
FIGURE 4.15 Autodesk Print Utility preview of the finished model for printing on a MakerBot.
- For more information on how to send your model to a 3D printing service, go to Chapter 16, “Using a Third-Party 3D Printing Service Bureau.”