In this installment of our Fusion 360 tutorial, we look at rendering your 3D models to make them appear realistic.
Rendering your 3D model with textures can show you how your model is going to look once it has printed. This can be useful to determine if you need to make any modifications before you print.
Take, for example, our Constant Current Dummy load from Issue 22. For this project, we designed an enclosure to house the electronics. We used the render process to get an overall look and feel of the device before we pressed print. This helped us make sure the end case would look aesthetically pleasing on our lab workbench, but also ensured the design was functional. The render gave us a chance to make sure the text on the front panel wouldn’t be covered by the knobs, for example, saving us from having to reprint the panel.
DESIGNING A GLASS MUG
For this rendering tutorial, we will model a glass mug. This will use some of the techniques we have discussed in the last few issues, including revolve, blend and sweep. (Fusion 360 has had a small update since the last issue and as such some of the button icons may appear different).
Let’s get started by first sketching half of the mug’s shape onto a single plane, which creates a uniform shape for us to model.
Copy the dimensions shown in the image to get the same results, and then revolve the sketch 360° around a centreline.
The base of our mug measures 61mm diameter and 71mm at the widest part. The mug measured 95mm tall.
Once you revolve the drawing around the centre axis, you want to start drawing the handle.
To draw the handle, create an offset plane that is level with the edge of the mug. On this plane, draw a circle 10mm in diameter and position it 13mm from the bottom of the glass. This will form the shape of the extrusion that will create the handle.
To extrude it to the shape we want, we need to create the path for this to extrude along.
Draw the line, as shown here, by using the spline tool.
Note: This path was very difficult to measure using calipers so it is an approximation of our actual mug.
Once you’re happy with the results, use the sweep tool to extrude the handle along this path.
Your 3D model should look similar to this.
To make our mug have a glass appearance we need to define the substance and material that the model will be made from. In our case, we will make our model have a glass appearance but you could choose an alternate material depending on your application.
Highlight the entire model by holding the left mouse button down and dragging over the entire model. With everything selected, press the ‘A’ button to open up the appearance menu. You will notice that there is a long list of textures to choose from.
You can search or scroll down to find and select the ‘Glass-window’ option.
To make your model a solid object of this glass material, simply click and hold the texture and drag-and-drop it onto your model.
You should now have a digital model of a mug with a glass appearance. Of course, this on its own isn’t very impressive. It’s simply now just a model of a glass mug floating in midair. If we were to attempt to render it, we would get a very flat looking object with some pretty lighting effects, and nothing more.
For the best results, we want to add a realistic scene to compliment the object, and add some lighting effects and or realistically position the lights.
We could just use the inbuilt backgrounds in Fusion 360, however, they are generally pretty flat looking and never quite look as good when modeling a small item against them. Besides, we want to create some new geometry so we can have a bit more of a look at the appearance menu and some other available options.
Let’s create a scene where our glass mug model sits on a wooden table with a wall behind it, which is a scene you would expect to be using a glass mug.
First, draw this sketch with the dimensions shown.
Extrude it symmetrically 1000mm in either direction.
Hold down the CTRL button on your keyboard and select all six sides of the table surface using your mouse. With all six sides selected, press the ‘A’ keyboard key to re-open the appearance menu. Scroll down and drag the ‘Mahogony’ option from the Finished list onto your model.
We can already see that the scene is starting to look a lot more realistic with this simple change.
Repeat the same process with the back wall. We chose enamel glossy white paint as our material, but you can experiment with whatever you prefer.
To add more realism, we can add further detail into our scene by importing objects or decals.
Decals are 2D objects that you can import into the scene and are not dissimilar to stickers.
These are nothing more than an image that you can scale and position into Fusion 360. In some cases, you can have them join the face of an object to completely cover it.
For our purpose, we will import an image of everyone’s favourite electronics magazine DIYODE. We started with a 2480 x 3248 high res JPG file of the front cover of Issue 26.
To import this as a decal into Fusion 360, switch from the design workspace to the render workspace. To do this, select Render from the design drop-down menu.
You will notice an entirely new set of options in your work area and menu. These options allow you to create a realistic lighting scene, change textures, add decals, etc.
Select the Decal button in the menu to see the decal options. Here you can choose which image you wish to add into the scene and on what surface it will be placed. We will include the image we used in the resources section on our website, however, you can import any image you wish. It simply needs to have a high enough resolution proportionate to the size of other objects in your scene. I.e. You can’t simply scale an image designed to be the size of an A4 sheet of paper to fit an object the size of a billboard.
Select the image button from the menu and find the image you want to import on your computer. Next, select the face you want the image to be placed upon. In our case, we will have our magazine image lay flat on the table surface. Press the face button and click on the table face.
Click-and-drag the image around the surface/face for the best position. You may also need to use the scale XY option to adjust the size of the image to fit the scene. Note: We don’t recommend you use the individual scale X and Scale Y options because this will alter the proportions and give a distorted appearance.
Once you are satisfied with the location, placement, and scale of the image you simply press the OK button.
If you change your mind and want to adjust the image again, you can easily edit it by right-clicking the decal in the browser menu and select “Edit Decal“.
You should now have an image that resembles something like this.
Note: We extended the length of the table and wall to allow for the angle we wanted to render from.
It’s now time to modify the lighting and chose the composition i.e. the angles and framing that we wish to render. This is all subjective and comes down to your personal preference.
We decided to set a solid black background to increase the contrast and reduce the amount of bounce lighting. To do this click on “Scene Settings” in the menu.
We then need to set different parameters for the scene and choose a background or solid colour.
Since we want to use a solid colour, select background and choose solid colour from the drop-down.
Note: If you would rather have the lighting effects from the background, experiment with how different backgrounds affect the scene and choose one that is to your liking.
We picked a focal length of 82mm as it allowed us to have what we wanted in the scene. We did, however, need to crop a little from the image, which we will explain a little later.
We enabled the depth of field and set the centre of focus on the mug close to the top part of the handle. This is where we want to draw the eyes of the viewer when they first see this image.
We changed the Blur down to 0.332 as we wanted the image to fade off much slower (greater depth of field). At a value of 1, only things inline with the centre of focus were in focus and the magazine decal blurred quickly. This can have a huge impact on the quality of your render and you should take extra care here when picking a value. A value of 2 will create a small focus area in line with your centre focus point. The lower this number the wider this band becomes.
Note: When setting up your scene, remember the decal has no geometry to it. It is nothing more than a 2D image, and as such, it may look out of place in some low angle situations as there is no thickness to it.
Once you have the scene setup, you can start rendering the model.
You have plenty of options here and each has their merits, strengths, and weaknesses. We use the in-canvas renderer for setting up the scene and getting a general idea of how the render will look, whilst still allowing us to make small changes.
This process takes quite some time as any change resets the progress bar that you can see in the bottom right corner.
This will constantly perform sweeps of the scene, each one improving the quality of the render, reducing noise and increasing reflections and light bounces, etc.
The second option is to use the full render option, which you can select in the menu. This option has two options within it. You can use your computer to perform the render process or you can have the servers at Autodesk (the creators of Fusion 360) perform the render for you free of charge. Note: this may have a limitation in the number you can do on a hobbyist license.
We have a reasonably powerful CAD machine with an i7 CPU 16GB of RAM and a 1060ti GPU. This means using the local render option isn’t much of an issue as we have quite a bit of processing power. Despite this, to render the image in final quality with a resolution of 3300 x 2550 it still takes around 2.5 to 3 hours to render.
During this time, the computer is under constant heavy load and, as such, even tasks like word processing is a chore. It’s for this reason that you may choose to use the cloud render option as this frees up your computer to do other tasks.
If you choose to render using the cloud renderer, you can expect your image to be rendered within about 10 mins on the highest possible resolution of 3300 x 2550/8.4 MP in final quality. This is without a doubt a pretty awesome deal if you’re on a package with unlimited render credits. It frees up your machine to keep working on other things and is many times quicker than rendering the image locally.
Once the file has rendered you will have the ability to download it directly from the cloud when you see the completed thumbnails at the bottom of the screen.
Click on the image you wish to download from this list. This will bring up a screen where you can choose from some other options such as post processing, exposure compensation, delete or download. Pick the download option and select what file format you wish to download it as, and where you want it to be saved.
That’s it! You now have a high-resolution render of your 3D model. For your next project, try making different faces of a single object, different materials or colours, etc., to see how a multi-material print will look.
PART 1 - BEGINNERS GUIDE TO FUSION 360
PART 2 - CREATING CIRCULAR TEXTURED OBJECTS
PART 3 - BLENDING & SWEEPING