Photo-realistic rendering SketchUp

Creating Photo-realistic rendering SketchUp is not native to the program, and has to be done using a plug-in application. There are several plug-ins (or add-ons) available for the purpose, and we discuss a few of them in this blog post. Rendering is also a topic we look at in all SketchUp training courses.
The first thing to keep in mind is that up to the rendering stage everything is done as normal in SketchUp, following the same workflow and building techniques. It’s crucial that all of your geometry is solid, that is, you don’t have any flat planes with no depth. Photo-realistic rendering engines will not recognize flat surfaces. Another thing to keep in mind is not to have any gaps in the geometry, which can result in odd shadows being created. So the image shown here is an architectural model of the Rose Seidler House in Sydney, NSW, built in SketchUp.

The process

The process of creating Photo-realistic rendering Sketchup follows the usual steps in that the architectural plans and CAD elevations were first imported into SketchUp Pro. And various materials native to the program, as well as some imported into SketchUp, were applied to the various surfaces of the model. The model was then geo-located for Sydney, so that the shadows will be accurate for any time of the year.
There are many render engines available for creating photo-realistic looks to the model. Some are free; many are available for purchase. The latter also have free trial versions you can download. And the prices range from a few hundred dollars to a few thousand. Among the freebies are Maxwell, which is a good place to start for the beginner. One issue with Maxwell is that you have to replace the SketchUp materials with Maxwell‘s own materials, which, while they are better, adds another stage to the development process. At the high-end of rendering is the expensive V-Ray for SketchUp which costs around $1500 Australian. A more modestly-priced option is LightUp which is produced by a British company. You can download the free 30-day trial version from the LightUp website, then decide whether you want to buy their product.

The Interface

LightUp has a very simple interface consisting of just four buttons on toolbar which appears inside SketchUp itself. The buttons are for adjusting the rendering properties, for initiating the rendering process, for adding lights, and for outputting the render as a still image or video. When Photo-realistic rendering SketchUp for an exterior shot like the one shown here we simply use the sun’s lighting provided by SketchUp‘s own Shadows function. Photo-realistic rendering Sketchup works on the settings for the time of day and year, there will be variations in the lighting. For example, shots rendered at sunrise and sunset will have softer lighting which tends towards the warmer hues of the colour spectrum. Mid-day lighting will be sharper and more blue in tint/temperature. In addition SketchUp adds a realistic sky with clouds.
When you hit the render button LightUp projects virtual photons in all directions – LightUp calls these M-Rays. This may take a few minutes, depending on the complexity of the 3D model. We start off with a small resolution to create a faster test render. Then we gradually increase the resolution to give us our final result. So we could start with a Resolution (in Properties) of 20cm and decrease this in later renders to 5cm.

Properties

We also have to note in Properties whether this is an interior or exterior scene. You can also choose the Custom setting and change this from 3m to 1m. Depending on the size of the room, this may wash out the shadows too much, therefore change it back to 3m. In this way we change each setting one at a time, and create a still image, so that we know exactly what parameter is causing the changes. Also uncheck Incremental Render and Ignore Cashe for a clearer resolution – it takes a bit longer to render (maybe a few minutes instead of a few seconds) but the result is better.
In the Stroke section untick the Edges field. Also, for outdoor models, change the Sun Multiplier to 0.7, for example, tick Real Time and make it’s swatch pure Black (0,0,0). In the Screen section: Combine with AO (Ambient Occlusion) – make the top swatch white (1,1,1) and the bottom swatch black (0,0,0). In the Linear Dark/Bright section change the multiplier value to 0.5 (for shadows).

Materials

Another great plus when using LightUp is that it simply uses the materials applied within SketchUp – you don’t need to use special material from the render engine itself.
When Photo-realistic rendering SketchUp for interior shots we can add a large range of lighting types, from spotlights to “omnis” which cast light in all directions. We can also use photo-metric lights which simulate lights in the real-world in terms of temperature and tint and intensity. You can specify the wattage, fall-off, specularity, etc. This is probably the most time-consuming part of rendering – getting the balance of lighting and shadows right for interior shots.
One tip in this respect is to create a nice lighting setup for a medium size room, group the lighting components, then simply copy the setup into future models. You could also have an outdoor setup, as well as setups for small rooms and large rooms. In this way you can predict how the lighting will fall with a minimum of later tweaking.

Foliage

Adding foliage to a scene can slow down the render time significantly, so it’s best to move the foliage to their own layer, and make it invisible until you have test-rendered the rest of the geometry to your satisfaction. Then turn on the visibility of the foliage layer, and re-render. This could take a while, which is why the traditional icon for the Render button in many render engines was a teapot! But rendering is a fairly fast process, usually only taking a maximum of a few minutes for most models. The great advantage of LightUp is that if you’re not totally happy with the camera’s position you can move it and the rendered scene will update automatically. In older programs you had to re-render the whole scene.

When Photo-realistic rendering Sketchup you can output the final still image into a variety of file formats: JPEG or PNG for web images, TIFF for commercial printing, etc. And with the pro version of LightUp you can choose larger formats for printing purposes, eg real-estate signage.

In summary, Photo-realistic rendering SketchUp can be an easy process, depending on the plugin software you choose. We have recommended LightUp for affordability, its ease of use and learning, its fast rendering, and seamless integration with SketchUp. The next level of rendering would be the higher-end (and more expensive) engines like V-Ray for LightUp, Artlantis and Lumion.
Many useful tips and techniques can be found at the SketchUp website. And see many examples of our own clients’ work on our Facebook page.
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