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Message |
    
support@formZ.com
Moderator
Username: Tech
Post Number: 5006
Registered: 04-2001
| | Posted on Thursday, April 24, 2008 - 03:15 pm: | 
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Kea,
We are moving your posting:
... from THIS thread to a new discussion here because the other discussion is from 2002, and your topic does not directly relate to that one.
We are reposting this portion of our previous answer, because it may help the continuity of this thread, as well as others..
quote:Below, please find some general tips for rendering with Global Illumination.
Always start by setting the correct Scene Size. Then, for best performance set the Quality and Level of Detail to 1. Always render with the RenderZone Renderer set to Raytrace whenever rendering rendering with Ambient Occlusion (AO) -- or if you have a multi-core / multi-processor computer.
Ambient Occlusion generally gives you the biggest improvement in image quality in the shortest amount of time. So that you can see the effects, increase the Ambient Lighting Levels (perhaps to 30 - 60%) or increase the Additional Contrast Option. Using a high ambient can also reduce the need for other fill lights in a scene, and allow you to concentrate on using accent lights only where necessary. If you wish to optimize AO, turn off the option to Receive AO for any little objects where this will not be noticeable. (Leave Cause AO On -- unless you specifically do not want to see this.)
If you have a scene where the bouncing of Light is important (such as interior renderings -- especially with daylight), it can be very helpful to add Final Gather (with or without Radiosity), although this can add some time to the rendering. To optimize this, turn off Cause and Receive FG or Radiosity (if you are using these and do not need to see the effects on certain objects). You can also use the Radiosity Bounding Box to limit what affects the calculations. And if you want to use Radiosity, you can typically get good results in a very short period of time (perhaps 1-5 minutes of Radiosity for a file for many types of files).
Once you have been able to get the desired lighting levels, look to see if you notice any shading artifacts in the AO or FG, you can then increase the Quality setting. Typically 3 is a good setting for a final rendering, and often you can get away with 2 without noticeable artifacts.
Of course there are many settings in terms of lighting, surface styles, geometry, etc that affect a rendering, so you should also see the Rendering section of our Frequently Asked Questions:
http://www.formz.com/support/faq.php
If you need help with a specific file (after you have attempted to make the noted changes), feel free to send it to us. We can take a look to see what additional changes can be made to improve quality and performance.
Hope this helps,
ZWebTech Support
Below, please find some suggestions to speed up and improve the quality of your rendering:
1. Don't use double transparencies: If you are going to use a Glass Reflection, you should generally set the Transparency to NONE because the Glass Reflection already has a Transmission component, which controls how the light will pass through. If you want this to be more transparent, increase the Transmission, and / or reduce the Reflectivity. (You will probably also want to select a less dark, less saturated blue color.)
2. To further speed up the rendering, you should set your ground plane to Render as Backdrop (via Query Attributes) and also turn off its shadow casting.
3. If you would like to generate a night time rendering, you should reduce the intensity of the sunlight and the ambient light (perhaps to ~30-50% each) and add some large Point Lights (perhaps a half-dozen of them, one in each of your large spaces). These Point Lights should use a Non-Constant Falloff, and if you don't need to see the shadows of the mullions outside the space, you can turn their shadow casting off.
4. For an evening shot, your Sunlight should be moved down to have a lower angle relative to the horizon.
5. Since the sunlight in your background image is coming from the opposite direction, you should probably mirror the background image (in Photoshop). You will probably also want to darken the horizon of this image.
6. You should also select all of your detailed plant elements and cars and use the Set Attributes tool to turn off Receives Ambient Occlusion so your file renders more quickly.
7. Your "entourage" symbols make up most of the data in your file. Put your people, cars, and plants on separate layers (they mostly are now), and turn them off when generating your test renders so you can see the results more quickly.
8. You can turn off the Ambient Occlusion while you are tweaking your lighting to speed up the test renders. (Just keep in mind that the Ambient Occlusion will make surfaces near other surfaces darker when you turn this back on again.)
9. You can also use the Set Image Size RenderZone Option so that you can just render a portion of the screen so you can see the effects of your changes more quickly.
10. It is fine to have Antialiasing off for test renders, but you should turn this on for final renderings (from the Shading Tab of the RenderZone Options).
Hope this helps,
ZWebTech Support |
support@formZ.com
Moderator
Username: Tech
Post Number: 5008
Registered: 04-2001
| | Posted on Thursday, April 24, 2008 - 03:59 pm: |
|
Ok, and a couple more:
First, here are a two excerpts from the above mentioned FAQ's:
(The FAQ is REALLY useful, so we recommend that anyone -- beginner or advanced -- at least glance through the questions -- if not the answers...)
11. You have Transparent Shadows enabled, but they will not add much to your image. Turn this off for speed, and set shadows to Raytraced.
12. You probably do want to get a different background image. Mirroring your image will help, but the sun will still be coming from behind your building, whereas your light will be coming from behind your view, which will conflict with each other and make the image seem wrong, even if the observer can't tell why.
13. Your project is about a mile from the origin. This is not bad, but I generally prefer moving a file so it is more centered on the origin.
14. You have added Glow to some of your surface styles (such as the parking stripes). While this can be a good idea for Light objects or parking stripes (during a day scene) the stripes will appear too bright in a night scene, so you will probably want to turn off this glow for your night rendering.
Good luck!
ZWebTech Support |
Kea Lim
New member
Username: Kea
Post Number: 20
Registered: 01-2008
| | Posted on Thursday, April 24, 2008 - 07:05 pm: |
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Zweb,
Thank you for the detail step by step explanation. I don't think I can get this kind of help form other support.  |
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