Adjusting Light Source Parameters

You can access the light source parameters.

1. Right-click the light in the specification tree.

2. Select Light object > Definition to open the Properties dialog box:

   
   
   

You can modify the lighting parameters.

1. Select the Lighting tab.

2. If you want to modify the source type, in the Type list select Spot, Point or Directional.

3. Use the Color slider to modify the color intensity, then click if you want to choose another color (the default color is white).

   For more detailed information, refer to Applying a Color Using the Color Chooser.

4. Use the Intensity slider to define the light intensity or enter a value directly in the box.

5. Click to define the intensity more precisely.

   For more detailed information refer to More about Adjusting Light Source Parameters.

6. The Falloff box lets you define the More about Adjusting Light Source Parameters (which is set to None by default).

7. Use the Angle slider to modify the source angle. The source angle defines the half-angle of the cone, that is the angle between the axis of revolution and the cone edge (for spot light sources only).

   The angle is a value between 0 deg and 90 deg. This means that a value of 90 deg would generate a light source equivalent to a punctual light source.

   

8. Use the sliders in the Attenuation area to modify the lighting attenuation parameters.

   For more detailed information on the attenuation parameters, refer to More about Adjusting Light Source Parameters.

You can access the physical light parameter.

1. Right-click the light in the specification tree.

2. Select Light object > Definition to open the Properties dialog box:

   
   
   

You can modify the lighting parameters.

1. Select the Lighting tab.

2. If you want to modify the source type, in the Type list select Spot, Point, Sun or Photometric.

3. Use the Angle slider to modify the source angle. The source angle defines the half-angle of the cone, that is the angle between the axis of revolution and the cone edge (for spot light sources only).

   The angle is a value between 0 deg and 90 deg. This means that a value of 90 deg would generate a light source equivalent to a punctual light source.

   

4. Choose the color model between RGB and Temperature.

   If you choose RGB, use the Color slider to modify the color intensity, then click if you want to choose another color (the default color is white).

   For more detailed information, refer to Applying a Color Using the Color Chooser.

   If you choose the Temperature option, use the Temperature slider to modify the temperature.

5. Use the Luminous intensity slider to define light intensity or enter a value directly in the box.

6. Use the Angular attenuation to modify angle attenuation or enter a value directly in the box.

You can modify the light source position.

1. Select the Position tab to define the light source anchoring point and the point to which the source is directed, respectively in the Origin and Target areas.

   You can define this position in millimeters along the X, Y and Z axes.

   
   
   

   Tip: Note that you can click the Reset value button at anytime to reset the light source to the default position.

2. The Reference Axis area lets you define the light source position relative to the Model axis or to the Viewpoint according to the option you select:

   
   

   • Model

     By default, any light source you create is positioned relative to the model and thus, moving the viewpoint moves the light source along the model.

   • Viewpoint

     Attaching a light source to the viewpoint means that moving the viewpoint only moves the model; the light source keeps the same position in the window.

     When a light source is attached to the viewpoint, it is identified by an anchor symbol in the specification tree as shown below for Light.1:

     
     
     

   Tip: You can also attach a light source to the viewpoint by right-clicking it in the specification then selecting Attach to View. Inversely, once a light source is attached to the viewpoint, you can re-attach it to the model by clearing Attach to View.

3. Click OK to validate the new parameters.

You can modify the area diffusion.

1. Double-click a light from the specification tree or directly in the representation.

   The Properties dialog box opens.

2. Select the Area tab to delimit the diffusion area.

3. Modify the parameters you can find in the Geometry frame.

   The options presented help you to define the surface of the light diffusion.

4. Click OK to validate the new parameters.

You can modify the indirect illumination.

1. Double-click a light from the specification tree or directly in the representation.

   The Properties dialog box opens.

2. Select the Indirect Illumination tab to define the indirect illumination you need.
   
   

3. Activate the Emit Photons option.

   The Intensity Factor parameter is now available.

4. Move the bar or use the Up and Down arrows to choose the value you want for the Intensity factor.

5. Click OK to validate the new parameters.