How to Render Realistic Ice in KeyShot
Step 1 – Creating the model
Open SolidWorks and create your model. Here you can see that the glass is made with a simple ‘Revolve’ feature, and the cubes are duplicated and stacked with many ‘Body-move/copy’ features. Since this tutorial is about KeyShot, I’m assuming that you know your way with SolidWorks, or already have a model to work with, and so I won’t get into the details of this particular build. (Note: You can also use this model of Ice Cubes found on GrabCAD.)
Step 2 – Import to KeyShot
Open up KeyShot, and insert you model via drag & drop or the “Import” button. Initially, you will see the entire model painted white. Open up the ‘Project’ window by pressing the spacebar or from the button below. Here I already renamed the parts to ‘glass’ and ‘ice’, so I would know what I’m working on. I selected all the ice parts and ‘Unlinked’ their material association.
Step 3 – Change the material
For the glass, I changed its material to ‘Solid Glass’. I left all the options at their default.
Step 4 – Adjust material settings
Next, I selected one ice cube, and assigned a ‘Liquid’ material to it. Crank the ‘Refraction Index’ all the way to 3, set the ’ Refraction Index Outside’ to 1.5, and ‘Transparency’ to 8. Then set the color to Red:220|Green:230|Blue:255.
Step 5 – Create the texture
The ice cube will become clear, but there is still something missing. If you look at frozen ice, it is nearly always not entirely translucent. This is because as the water freezes, air bubbles and particles in the water, get caught up in the frozen ice. To achieve the icy look, we need to set a bump and opacity map, and for this we need to create a texture in Photoshop. Open Photoshop and create a new empty document with the size of 5000X5000 pixels with a white background.
Then, create a new empty layer, and put it below the background layer. To do this, right-click on the background layer and select ‘Layer from background…’. Set a mask on the white layer by clicking on the “Add layer mask button”. The reason I’m using a mask is that I can always change or replace the mask without affecting the image layer itself. Now take a large bristled brush, and paint on the mask with black color, leaving a “frame” around the corners of the page. Don’t worry about getting it all fully black, we want some white and gray shades to show through the middle. It helps to put a black background to get a better sense of the result. Eventually, what you will get, is a white frame with no background, that resembles cracked ice.
Step 6 – Save the texture
Go ahead and save that file as a PNG. The PNG file type can contain transparency, as opposed to JPEG. And now you have your texture.
Step 7 – Apply the texture
In KeyShot, head back to the ‘Material’ tab in the ‘Projects’ window. Go to the ‘Texture’ tab, and set a ‘Bump’ and ‘Opacity’, by choosing the newly created texture file. Hit the ‘Sync’ checkmark, so that if you decide to change some of the properties, it will link the bump to the opacity. That’s it, your new ice material is complete. At this point, you can save the new material in the material library for future use.
Step 8 – Copy-paste the material
Return to the ‘Scene’ tab and copy-paste the ice material to the rest of the parts.
Step 9 – Adjust the Advanced settings
The ice looks much better now, but it still looks opaque. This is because of the way that KeyShot renders light through materials. We have to go to the ‘Settings’ tab, expand the ‘Advanced’ section and increase the ‘Ray bounces’ from the default 6 to 12. This may differ in your project, so be sure to play with the value till you get the right one. And don’t just put a high value, as the rendering can take unnecessarily very long. Next, turn on ‘Global illumination’, and if you like, put a nice darkened ‘vignette’ to the scene. I didn’t increase the bloom in this scene. I will talk about the ‘Bloom’ setting in another tutorial.
Step 10 – Apply the environment
Things are looking great, but we still need to set a lighting environment. Open the “Library’ and set a nicely contrast environment. I chose ‘3 point sharp high 2k’.
Step 11 – Adjust the environment
Back at the project menu, head to ‘Environment’ and change the settings to your liking. I chose to put a color behind the model, instead of the ‘Lighting environment’, and set it to a deep cool gray (Red:3|Green:3|Blue:4). If you like, check ‘Ground reflections’ on.
Step 12 – Adjust the camera
Next thing to do is to set a camera, so head to the ‘Camera’ tab at the projects menu. Click on the ‘+’ to create a new camera, give it a name, and click “Enter edit mode”. Set everything to your liking, including a depth of field, to create the feeling of a close up shot. By adjusting the “F-stop”, you can make the object out of focus more blurry, but careful not to make it to blurry, just enough for it to look real. When you’re done, click “Exit edit mode”, and then “Lock camera”.
Quick tip – if it takes too long to move the camera around the object, try hitting ‘Alt+P’ to temporarily pause the real-time render engine.
Step 13 – Set up your render quality
Now let’s go to the ‘Render’ menu. First, jump to the “Quality’ tab, and set the quality as high as you like the result to be. Cranking up the ‘Samples’ will give a higher quality render, at the cost of time. Also increase the “Depth of field” value, as we are using depth of field in the scene. And last, check that the ‘Ray bounces’ are set to 12 (or what you intended it to be).
Step 14 – Render/grab a drink
Now head back to the ‘Output’ tab. Set your required image size. The more pixels you have, the better the result would be fit for printing. You can get the pixel equivalent for centimeters/ inches by opening a new document in Photoshop and changing between sizing methods. Also, as you can see blow, I chose to save as TIF, because it would give me an image with no background. I prefer to create the background in Photoshop, and this way I have complete control of the rendered model and the background, separately.
In this manner, you can later seamlessly implant the object into a previously rendered scene or a photograph. At this point, you can choose to render to JPEG, as we already set the desired background in KeyShot, but I still want to tweak the final image a bit more in Photoshop. Hit the ‘Render’ button, and go grab a drink, it’s going to take a while… :)
Step 15 – Final output!
And here is the result – a high quality rendering that took nearly 10 hours! It took that long because of the complexity of the layered transparent parts, and because I set the sample rate relatively high. In general, rendering time is also affected by part’s opacity, and by depth of field and other visual effects (such as bloom).
And finally, here is a full resolution image of his drinking glass submitted for his ‘Concepts’ course. Bottoms up.