If there is one thing I did a lot of during the weekend, it was (No, not procrastination!) digital rendering. I learned a bunch of things about rendering, both from practice and from the internet. I thought these could be useful to us designers. Most of what we are going to be dealing with might already be a part of your workflow, but I hope you’ll learn something new reading this post.
I’ve split this article into three sections: preparation, set-up and rendering. The entire rendering process needs more attention and planning than it is usually given by us. Let us get to it then!
Preparation involves getting the model ready to be imported into the rendering software, in this case, Keyshot. Preparation begins at the modeling software, in this case SolidWorks. What I’ve found to be easy for me, is to apply different colors onto different parts of the model/assembly. This helps Keyshot detect the different components, faces or surfaces of the CAD model. I realized that if the entire assembly is imported into Keyshot as a grey model, the separate parts are not detected. You could search for and apply the materials to the model in SW and then import it, but KS doesn’t detect the materials in that case and so, its a waste of time. Once you’ve applied the colors to the places where you have different materials, the model is ready to be imported into KS. If it is an assembly, my suggestion is to assign different colors in the assembly file and let SW apply the changes in the part document level. It eases the process for you, and prevents you from making the mistake of choosing the same color for different material areas.
Another major thing to keep in mind at this stage are the corners and edges of our model. As designers, we know the importance of having filleted corners and edges from a safety and liability standpoint. But it also helps in achieving a good render. Light is captured better by a filleted corner than by a sharp corner.
Once the model is placed in the rendering environment, we can apply materials, textures and lights. I prefer turning off performance mode while applying materials and lights. This helps speed up the software. I don’t need to see what it looks like before I set-up other essentials.
Performance mode : OFF Performance mode : ON
A good thing to keep in mind while applying materials is to try mimicking what the product will actually be made of. For instance, if the product has a plastic coating with a metallic grey color, apply a plastic material with a grey color and tweak the roughness, rather than applying a grey metal material to the model. This will help achieve a look closest to a real world appearance. You might be able to achieve this with even a metal material applied, but its good practice to apply accurate materials.
Lighting set-up is another subjective area. I have seen people render with the default settings, with tweaks to just the brightness and contrast settings. I’d suggest changing the lighting to suit our model. I usually always change the lighting to suit my model. This means having a different HDRi setting for each render.
My set-up stage goes like this:
- Remove all the lights preset by the program. Even ambient/global light. I like to begin with a dark environment so that I know what each light is doing. This lets me tweak the lights as needed.
- In the HDRi light studio, I first add and position a single light source. I change the color to something weird like a yellow, red or pink etc. This lets me see the area it illuminates accurately. Stay with me now!!
- Every light I add has a different color so that I can accurately control its illumination of my model.
- Add and test each light individually and then test again with all the lights. Once the illumination is satisfactory, change the color of all the lights to whatever you need.
- Move the model to make sure the shadows indicate if the position of the model is either on or above the ground.
Next come the textures, maps and roughness settings. Now, I turn on performance mode to reflect the changes I make to textures and maps, in real-time. This is the end of the set-up stage.
Once the model begins to look nearly realistic, I do a test render. This is done on low settings to get the render done quickly. Based on the render results, I tweak required settings. After a few iterations, I do a final full-size, high-res render. Mostly, I save it as a PNG file. Open the render in an image viewer like Preview (Mac) or Image viewer (Windows) to check if it resembles actual materials. If yes, awesome! We’re done! Else, tweak settings, render and check again.
I did not talk about applying graphics, logos or maps, although they are very important in providing realism to the models. This part of the rendering workflow is for a future article.
I hope you learnt something new from this article. Let us become better designers, one article at a time!! Haha!