IRender Presets Tab

The Presets tab is used to select redefined lighting settings and make adjustments to them.

nXt is designed to simulate real-world lighting. Use the following guidelines when lighting your model:

Provide accurate information whenever possible. Avoid using unrealistic intensity levels for light sources.
Adjust the overall brightness of your rendering by using the Brightness control on the rendering display. Do not attempt to adjust the overall scene brightness by changing the intensity of all of the light sources. nXt's automatic exposure adjustment will be working against you if you attempt to do this.

Lighting Presets

nXt provides four lighting presets which can help get you started when deciding how to light your model. There are many more lighting options available, but the presets are often sufficient for many different renderings. The Presets icons are available on the Presets Setup Tab. Choose the Preset which most closely resembles your scene:

High Dynamic

mimics the lighting which might be found in a photographer's studio. It is most useful for rendering small to medium sized objects in isolation.

The primary lighting is provided by an high dynamic range image file (HDRi). The light from the HDRi has been artificially dimmed, to resemble the interior lighting levels of the studio. You can modify the HDRi settings and file on the HDRi Setup Tab . You can add artificial lights to your scene using the Lights tab.

Exterior

is used for daylight simulations of architectural exteriors. A sun and natural sky are simulated.

The sun and sky settings can be modified on the Sky Setup Tab . You can specify sun angles directly or you can use geographical location and date and time. The default visible background for this preset is the simulated sky.

Interior with Sun

Interior Daylight allows you to simulate an architectural interior during the day, lit by natural light.

For an interior daylight simulation to work properly, you must use a transparent material to represent the glass in your windows. Sun and sky settings are similar to the Exterior preset. Interior Lighting.

Interior - no Sun

provides a simulation of an architectural interior at night, lit by artificial luminares.

For this simulation to work properly, you must add artificial lights to your model.

Additional Notes on Presets

Indirect lighting, the lighting reflected off of surfaces, is on when one of the two interior presets are selected and off for studio and exterior. This type of lighting is a very significant component of an interior simulation. For exteriors and studio models the effects of indirect lighting is more subtle. You can turn on indirect lighting for exteriors and studio models if you want this additional realism (at a substantial performance cost.)
Interior daylight mode and exterior mode do not have artificial lights enabled. You can add artificial lights to these presets if you wish by following the procedure here.
Night time renderings can be a little tricky.

Presets tab

Image:Interior 72.png

The Presets Tab lets you choose predefined settings more the most common lighting situations.

The Presets set items on the bottom of this tab which can also be altered directly.

Preset	Description	Usage
High Dynamic	(default) Uses an HDRi sky for reflection and illumination which is very effective for many renderings without using the sun or any exterior lights. This provides a nice lighting effect for viewing individual items. See: High Dynamic Lighting	- exterior scenes or isolated objects when you want to create an interesting, subtle, lighting effect, inst4ead of using the sun or interior lights.
Exterior	turns on the sun and the sky, and high ambient lighting.	- exterior scenes when the effects of sunlight are desired.
Interior w/sun	turns on the sun and the sky, and lowers the ambient light so interior lights will be effective as well.	- interior scenes with windows and interior lights. If you do not have interior artificial lights, then use Exterior instead.
Interior - no sun	turns off the sun and sky, with lowered ambient lighting.	- interior scenes with windows, or scenes with windows when the effect of light coming in through the windows is not desired.

See Preset Details}

The settings below override the Presets: SketchUp on/off

Sun' - turns on the SketchUp sun
Sky - turns on the SketchUp sky
Ground Plane - turns on the SketchUp ground plane.

Sky Mode

SketchUp colors - make a background sky which emulates the coloring of the SketchUp sky.

The SketchUp colors sky does not reflect or illuminate the drawing,

Automatic - creates a realistic sky which illuminates the model.
HDRI - uses a HDRI image to define the sky.

Ambient Light
Each setting provides a smaller amount of ambient light to better represent scene selected:

Exterior
Interior
High Dynamic
None

Other Settings

Use Indirect Lighting - Incorporates the effects of indirect lighting. (Lights reflecting from mirrors and other surfaces.) See; Indirect Lighting
Sky reflected if off - produces reflections from the sky even if it is not visible.
Sky illuminates if off - produces lighting effects from the sky even if it is not visible.

These last two settings are useful for High Dynamic illumination effects.

Use Background Image - Places a background image behind the rendering.

See: Background Image

Preset Details

Feature	Description	High Dynamic	Exterior	Interior w/sun	Interior - no sun
Sun on	Turns on the SketchUp sun	off	on	on	off
Sky visible	Turns on the SketchUp Sky.	off	on	on	off
Sky reflected if off	Sky is used for reflections even if it is not visible.	on	no change	no change	off
Sky illuminates if off	Sky is used for lighting and shadows even if it is not visible.	on	no change	no change	off
Sky type	HDRi (uses image for illumination and appearance) or Automatic - generated from sun position and brightness	HDRi (Forest)	Automatic	Automatic	No
Sky HDRi	HDRi image used for sky reflections and illumination	Forest (rnl_probe.hdr)	no change	no change	no change
Daylight Mode	Amount of daylight used in the scene	low	high	medium	medium
Indirect Lighting	calculates effects of reflected light. See: Indirect Lighting (not available in nXtRender)	off	off	on	on
Auto Daylight Portals	makes all transparent surfaces act as daylight portals. (not available in nXtRender)	off	off	on	off
Artificial lights	Uses illumination from exterior lights	off	off	on	on
Studio Brightness	Lowers ambient light for High Dynamic lighting	on	off	off	off

See also