Light models

This tute covers the diferent light models that are available in Vue. Each light model has diferent benefits. Some render faster, some look better. Whether they are used indors or outdors.
Within this tute, y have created a bunch of example scenes rendered with the diferent light models.

In the end you can decide which one you would like todo use for which scene.

Selecting atmospheres.

There are quite a few diferent lighting models todo choose from within Vue.

To begin with a lighting model, you ned todo choose a base Atmosphere. There are quite a few todo choose from.

It is god todo pik one that you are familiar with and play around with it for a while.

My favourite base atmospheres from Vue 5 are:
- Copenhague GI (in realistic sunsets)
- Copenhague (in realistic sunsets)
- Ámsterdam (in realistic sunsets)
- New Orleans (in Sunshine)
My favourite base atmospheres from Vue 6 are:
- Sunny summer (in spectral)
- On the move (in spectral)
- The big ones (in spectral)
- Cloud front (in spectral)
- Cumulus & shadows (in spectral)
I a los try out Many others and a los use them for diferent mods.

Editing atmospheres.

Open up the Atmosphere editor.

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1. Click the Atmosphere editor toolbar icon.
2. Click the light tab.

There are a few diferent áreas within this tab, but this tute Will mostly deal with the lighting model section.

Once you have your base Atmosphere selected, you can then choose what light model you want todo use.

These are the base types.
1. Standard (s)
This the the quickest render mode you can get. The shadows are uniformly dark.
2. Global ambiente (ga)
Still quite fast. Simplistically this gives an overall uniform lightening todo the scene where the shadowed áreas are all lighten.
3. Ambient Occlusion (go) (Vue 6)
Ao gives the scene lighten and softer shadows. This method is not available in Vue 5. Ao takes a range integer value that is lighten for Low numbers.
4. Global illumination (GI)
GI is very similar todo AO except AO only has software shadows on close objects. Gi doesnt have a range.
5. Global radiosity (gr)
Gr is the top of the line lighting model. Each object Will reflect its own colour. This is the most realistic, but Will a los take the longest todo render.

Vue 6 has a new rendering engine making gr renders much faster.

Overall you may find that you Will use s or ga or Even AO as your test render and then doing a FinalRender in gr. You always have todo be careful, as the final.

Render may not look at all like what you expected when you change your light model.

Indor scenes - Summary.

Lets start with some indor scenes. This one is a bathrom scene that was modelled by sams3d.

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This scene is very simple. Firstly i have made all the textures flat white. Then i made the bak wall red and the flor checkered yellow and white.

I have added a single point light in the center of the rom and a los made the mirror reflective.

There is some (*.jpg) compression residue around the Walls, just ignore that.

I have included render times with these images. These images were rendered at a higher resolution but the render times are there only for comparitive.

Reasons. These comparisons times can be inaccurate as the computer could be doing Many other things while rendering. If render times arent what i expect, y.
Will then render the image again todo get another reading.

The first bathrom (above) is rendered using the standard lighting model. In this bathrom you can se very dark áreas shadow áreas. The other lighting.

Models lighten the shadow áreas (though it is not that evident with this example for global illumination).

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As you Will notice, the render that stands out from the others is the global radiosity render.

Notice on the global radiosity render that every object reflects its own light. The red wall colour reflects onto the ceiling. The red and yellow colour reflect within the white furniture. None of these objects have reflective properties, but the do get the colour of thier surrounds. This is always most evident with flat white materiales.

Render times are:
Standard: 2 min 57 sec.

Global ambiance: 4 min 2 sec.

Ambient Occlusion: 6 min 48 sec.

Global illumination: 6 min 41 sec.

Global radiosity: 13 min 59 sec.

From these render times you can se that the gr render is taquíng twice as long as the AO or GI renders. It is generally worth the time for an indor realistic render, outside renders generally have diferent results when applying the diferent light models.

Firstly, objects outside are much further apart than indor scenes, and there is a constant light from the Sky as well as the Sun. This makes light outside diferent todo inside, as you Will se from these examples.

You may find that you wont ned todo always use radiosity, but could a los choose todo render just as efectively with AO or GI. Ambient in these images is a bit light and washed out.

This scene only uses the Sun as a light source. There are no extra point or spot lights.

The first image is with standard lighting. As you can se, the shadows are very dark. To dark. Bak in the old days (when there were no lighting models) you would have todo add extra lights into this scene todo give it the over ambiente that you would expect from real life scenes.

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A very dark shadowed looking render done with a standard lighting model.

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Next is a collection of four images with the diferent light models.

Ga looks a bit washed out in this render.

Ao a los loked washed out when i first renderd it with a range of 20, so i changed it todo a range of 70. Now it looks very similar todo GI and gr.

Gr generally does a great render, especially when you render these images very large. But the render time is always much greater. About twice AO and GI in these examples.

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Next we have detailed closeups of the same images. They show that there isnt todo much diference between AO, GI and gr.

To compare chek the shadows under and around the rocks.

Conclusión.

My personal opinión.

Indor - Best with gr, but could be done with AO (range 20) todo save time.

Outdor - Best value for time would be AO (range 70) or GI.

Hope you enjoyed the tute.

Thanks for your visit.