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support@formZ.com
Moderator
Username: Tech
Post Number: 5023
Registered: 04-2001
| | Posted on Monday, April 28, 2008 - 01:15 pm: | 
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A user asked how to simulate the lighting for a sky. We thought that this answer might help more than just this user, so we decided to post the answer here.
Basically formZ offers 3 ways to illuminate objects from all sides. The first method is the Ambient Light setting, which can be accessed via Options: Lights. This is light that shines equally from all sides. By itself it is quite basic, but when used in conjunction with Ambient Occlusion (AO) can give nice results. The other two methods are implementations of what are called "DOME" lights. That is, a hemispherical dome is created around the project, and many individual lights are shined from all angles.
Atmospheric Light creates a distribution of lights to simulate the sky based on the Direct component of the light. Environment Lights use an image (HDRI or other) to determine both the intensity and the color factor for the lights that are distributed across the dome.
With Dome Lights you almost never want to use more than one. Choose one or the other type, and use these with other distant, point or cone lights, but not with other dome lights.
In the Dome Light Options, the number of samples determine how many lights are used to approximate the sky dome. The more lights, the better the quality, but also the longer the render times.
To see how these work, download the attached file:
Here we have a simple set of objects with a smaller window size. (This will allow us to get quick results, so we can experiment with more options.)
If you don't have the Scenes Palette open already, go to the Palettes Menu and open this palette. (To prevent unwanted changes to the scenes, always deselect a scene immediately after selecting it so that you can activate its settings, but not change them.) Also open or expand the Lights Palette to see the names of the lights, and which ones are shining when. (The circle to the right of the name of the light indicates that it is currently shining.) The Title of the Scene indicates the methods being used for the lighting.
Scene 1 uses a distant light only. Ambient is also used to illuminate all sides equally. Surfaces are well differentiated, the rendering is fast, and the lighting is very simple.
Scene 2 uses Ambient Occlusion to simulate environmental lighting. Its effects are nice, and fairly fast, but not extremely accurate.
Scenes 3 and 4 use the Atmospheric portion of a direct light (from the Light Options: Parameters Tab). With a low number of samples, the individual shadows are distracting, and you need to specify a higher number to smooth these out. Exterior renderings may need ~500 samples to get good shadows, but lower numbers can be used for test renderings to speed the process of positioning the lights and setting their intensities.
Scenes 5 and 6 use an Environment Light with low and medium number of samples. A distant light is used as well to generate the "direct sunlight" shadow. Depending on the image used for the Environment light, this may not be necessary, but in this case we are just using the formZ Logo so that everyone has access to the same file. Note also that if you are loading a darker image, you will need to increase the intensity of the light to compensate for this.
Scene 7 turns off the shadow casting for the Environment Light and adds AO to simulate the environment shadow.
Feel free to play with the combinations of these effects and the intensities of these lights (and make sure to uncheck the Scene unless you want to make changes to them).
See also our Frequently Asked Questions: http://www.formz.com/support/faq.php (especially the Rendering section).
The following posts may also be of use or interest:
Rendering Questions: http://www.formz.com/forum2/messages/16/26981.html?1209078321
Interior Lighting: http://www.formz.com/forum2/messages/16/27092.html
Dome Lighting: http://www.formz.com/forum2/messages/16/26647.html
This specific user help thread may also be helpful:
http://www.formz.com/forum2/messages/16/26981.html?1209064534
And we have some Demo Videos that show some additional rendering features:
Ambient Occlusion: http://www.formz.com/downloads/video/video.php?action=small&id=28
Sun Animation: http://www.formz.com/downloads/video/video.php?action=small&id=25
Final Gather and Radiosity: http://www.formz.com/downloads/video/video.php?action=small&id=27
Non-Photo Realistic Rendering: http://www.formz.com/downloads/video/video.php?action=small&id=26
Lighting: http://www.formz.com/downloads/video/video.php?action=small&id=7
And the general Demo Videos link: http://www.formz.com/downloads/video/video.php
And of course, hold down the SHIFT key when clicking on any tool or menu item in formZ to access the full documentation, or click on the ? icon from any dialog.
Hope this helps,
ZWebTech Suport |
Yousef Kurdi
Advanced Member
Username: Yousef
Post Number: 123
Registered: 09-2006
| | Posted on Tuesday, April 29, 2008 - 03:57 pm: |
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Awsome!! thanks ZWebTech, you're the best! |
support@formZ.com
Moderator
Username: Tech
Post Number: 5039
Registered: 04-2001
| | Posted on Tuesday, April 29, 2008 - 05:27 pm: |
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Renee Champagne
New member
Username: Renee
Post Number: 7
Registered: 01-2007
| | Posted on Thursday, December 04, 2008 - 04:17 pm: |
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When I down load the file it has a link of .unk
I can't open it. What is wrong? |
support@formZ.com
Moderator
Username: Tech
Post Number: 6356
Registered: 04-2001
| | Posted on Thursday, December 04, 2008 - 04:21 pm: |
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Renee,
Just add the .zip extension and unzip it...
ZWebTech Support |
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