Bounced light in LightUp v5

New Features Roundup

The following covers some new features of LightUp v3 which help improve your lighting times as well as increase the quality of the output.

Vertex Lighting

Setting Resolution in LightUp Preferences controls the amount of lighting detail; each SketchUp face has a virtual grid of lighting points laid over it for lighting. The finer the grid, the more detailed the lighting will be - and more time it will take. See the LightUp Essentials video for more explanation: http://www.youtube.com/watch?v=ywyI0vJNNzQ

For a regular sized room, you might use Resolution of '20cm' during draft renders and increase to '5cm' for final renders. However, there can often detail elements in your model that are smaller than 5cm (let alone 20cm), and these will show Aliasing Effects. The lighting grid is too large to capture the small details and increasing resolution for the entire model is overkill.

Here's a couple of example objects that have fine detail many of which are only a few millimetres in size. The 1 meter ruler nearby shows how small they are.

You can see a number of problems. On the sculpture, the curves of the model are much smaller than the lighting grid, resulting in a 'faceted' appearance. The vase also has dark spots and irregular lighting because the detailing is too small to be captured by the lighting grid. We could solve this by bumping up the Resolution, but in a larger context, this may not be practical. To the rescue is VertexLit mode for Groups and Components.

With LightUp v3, right-click on a Group or Component to mark it as 'VertexLit'. LightUp now uses the vertices of your model for lighting rather than overlaying lighting grid which for highly detailed meshes will often give a better result.

Now all the small details are perfectly lit with no aliasing, while still being able to use our chosen Resolution for regular lighting.

No Backface Culling

SketchUp faces have a Front-side and Back-side with separate materials for each. However, it is quite common to find models which have been created to be drawn just using front faces only - often models used in realtime systems just show the front faces and remove ("cull") Backfaces.

If you're modelling with single sided Faces and have "Double-sided" unchecked in LightUp Preferences, then your lighting time will be roughly halved and TourTool performance improved.

However there are times when you'd really like to be able say "I'm using single-sided geometry, but just for this Group or Component, I want to use Double-sided". LightUp v3, introduced a new setting that can enabled with right-click on the Group or Component called "No Backface Culling". Here is an example plant in single-sided mode. From the top it looks fine, but from below all the foliage has "disappeared" as we're looking at the back-faces which are not drawn.

We can fix this by setting the "No Backface Culling" attribute.

Lambert-Beer transparency

LightUp v3 improves the way light passing through transparent materials is handled to give a more realistic effect of light being absorbed more, the more material the light passes through.

Preview Thumbnail

Unlike other renderers, LightUp renders your entire model, not just what is "in view". This allows you to then navigate anywhere in your model in realtime.

When you're rigging up your model for lighting and trying out light positions and styles, you can get a rough thumbnail view of the effect by unfolding the Thumbnail Preview in Preferences to check the effect before starting off a full lighting process. The thumbnail is updated by clicking on it, so you navigate your model in SketchUp, add and remove lights and simply click the thumbnail to refresh. For larger models it will still take a few seconds but is typically quicker than running a full lighting cycle.

IES Rectangular luminous opening

IES files capture all the details of a physical light along with information about the shape, wattage, manufacturer etc of the luminaire. LightUp uses a special SketchUp Component that is automatically added to your models called "PointLightSource" to position and orient IES light sources. Although the default PointLightSource is represented by a small ball, if you assign an IES light that has a rectangular shape, LightUp takes account of this when lighting so you can for example add strip lights represented by IES files. This feature is automatic.

Edge Styling

SketchUp Styles allow you change how the Edges of your Faces are drawn. LightUp supports realtime features for showing (called "stroking") the edges of your geometry during TourTool. The width of the stroked edges can be edited in realtime by using the slider.


The color of the stroke can also be controlled using the SketchUp Styles dialog. A simple building shown in TourTool and editing the stroke color to a non-black color - here we've set it to Beige.

Lighting Sketchup Plugin