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Common mistakes in Rendering

Francis Robert - Tuesday, February 09, 2016

In this article, I’d like to expose common mistakes made by users when rendering their products. I saw too many bad images on web sites or other marketing documentation to state that modern rendering technology solved all problems.You have the tools to create really nice images; it’s up to you to use them to your advantage!

 

Everyone has a different level of artistic sense.It will obviously influence the result but I hope that by following these simple rules, you will create remarkable imagery.So, whether you’re the next Picasso or can’t draw a stick figure, you won’t have any excuses anymore.


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  • 1.Starting point
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Where should I begin?An interesting model will be easier to work with, of course, but we can still make a rectangular welded frame interesting.First : what NOT to do…

 


 

Dont’ laugh!I still see these kinds of images in some Case Studies! A Solid Edge direct screen capture can still be acceptable in many cases but you need to make some sort of effort…

 

  • a.Hide construction elements (coordinate systems, reference planes, sketches, PMI, etc) unless they are absolutely necessary. A simple right-click in     the graphics zone will help you do this in seconds.
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  • b.Crop the image so you don’t see the Edgebar, the Quick View Cube and how many Internet Explorer tabs you have opened.Focus on your product!
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  • c.Use gradient background.Many of you miss the old Solid Edge V12 background but still…
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  • d.Activate the high-quality display parameters. Raise the Sharpness and “anti-aliasing” levels.Activate floor reflection unless it causes distractions.Enable Perspective angle set to 35mm first, then tweak if required. Don’t hesitate to explore settings and save a 3D View Style to reuse later.

 


 

Let’s see what Solid Edge can look like, even without Keyshot:

 


 

Much better, isn’t it?

 

  • 2.Shifting in second gear!
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If you’re not satisfied with the image quality rendered by Solid Edge alone, level up by sending your model to Keyshot. In Solid Edge, go to the Tools tab and hit “Keyshot Render”.Let’s look at the “as-is” result, created by Keyshot by default:

 


 

Again, much better, no?Reasons why this is better are both simple and complex but one of the main reason is the lighting. By default, Keyshot lights up the model using its “Environment”.This is a rectangular high-resolution image wrapped on a sphere surrounding the model. Each pixel of this wrapped image acts as a light source, which gives a natural light and feels similar to what your eyes are used to see.

 

Moreover, the same environment image is used to generate reflections on the polished material present in the model. A simple change of environment can make a huge difference on the look of a render.Browse the Environment library, select an image you like and drag it in the graphic window of Keyshot.

 


 

Many control parameters are available to tweak the environment. See it for yourself in the Project section, Environment tab.For most users, simple parameters like contrast, brightness and rotation angle will be sufficient.Keyshot Pro adds a “HDRI Editor” tool, enabling you to modify the default environments supplied in the library and create your own.


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  • 3. More materials, less reflections!

 

There is a lot to say about Materials in Keyshot.I use the word « Material » because this aspect regroups color, texture, reflection, transparency, refraction and even decals.It’s far from a simple color!Let’s see common mistakes made at the Material level:

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  • a. Material mistake #1: Changing idea during the process…
  • The look of a material is strongly influenced by its environment and its camera point of view as well.This is even more obvious for “brushed” textures (stainless steel).Always define the cameras and environment before starting to tweak the materials.If you don’t, chances are you’ll have to start over again if you changed environment and point of view.
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  • b. Material mistake #2: Sharp edges…
  • In many industries, we model parts quickly without « removing sharp edges ».This is good for production, not for the CAD guy, but for rendering, it’s almost always preferable to add fillets and radii everywhere.The result will be much better and natural looking reflections than with perfectly sharp edges.
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  • c. Material mistake #3: Mirrors… mirrors everywhere!
  • You polished your model and applied mirror-like materials everywhere.This may have been a good idea at the time but your final image will hurt from this decision.One aspect is the render calculation performance going down a bit but mostly, it will be hard to distinguish the model surfaces, parts and even the background.

 

Let’s look at an example which combines mistakes #2 and #3.Polished material (Roughness is at 0.008) and sharp edge(zero radius):

 


 

Let’s add some rounds and fillets. You can do this in the CAD or with Keyshot Pro 6, use the “Rounded Edges” setting located on the bottom of the Scene tab (Project section).We also changed the Roughness value to 0.1 to reduce the mirror effect.See the difference with the image above:

 


 

  • 4.Conclusion
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Following these simple rules, you’ll be able to create beautiful realistic images of your products… without going to Art School!To conclude, let’s see the same model as our starting point rendered in Keyshot. The left side has sharp edges and polished material everywhere, the right side followed the guidelines. Happy rendering!

 

 

 

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