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John Cassel (cassel)
| | Posted on Friday, October 26, 2001 - 05:49 pm: | 
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I seem to be having a tough time of getting the underside and back corners of architectural surfaces lit. I've created a model of a large community center that is made up of a large roof with a few rooms under the roof. Ambient light washes out the whole model and I see that Jeremy Birn recommends against using ambient lighting. Setting large cone or point lights under the structure pointing up creates ghastly shadows.
What seems to be lacking is the natural light that would be bounced off of the surfaces (especially the floor and walls) of the building. The material that I am trying to model is basic concrete right out of the form. When I set the surface styles to reflective they also reflect images of adjacent structural elements as well as the people in the model.
I've been searching the forum and the web for tips on how to get this and other models lit. I don't need photo-realism--just a basically lit model that describes the architecture.
Is there a way to get universal overall natural lighting in my models or do I need to light each view one at a time?
I have noticed that some users model in formZ and then export to either Lightscape or Lightwave for lighting and rendering. Someone recently even mentioned that one of these programs had preset lighting scenarios. This actually sounds great to me as I would rather spend time creating the architecture than working on the rendering.
Would it be easier/quicker to export to one of these programs or is there a way to get good general lighting quickly in formZ?
Thank you,
John Cassel
PS I was about to buy Jeremy Birn's book "Digital Lighting and Rendering but then I read Josephus Holt's comments here on the forum ("lighting interior spaces" Oct. 13, 2001). Josephus mentioned that the book "addresses more the lighting of individual objects." That is not what I am looking for in a digital lighting book. I am looking for advise/tips/tutorials on lighting architectural models quickly and effectively. Any suggestions? |
Josephus Holt (holtj)
| | Posted on Sunday, October 28, 2001 - 12:05 am: |
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John, you won't find what you're looking for in Jeremy Birn's book. At the end of book are 2 pages on simulating radiosity for the interior of a room. That's helpful for me since the few renderings I've done were all interiors. Like most such books, you'll glean a little here and there out of it, however, the best (practical) help I've received is right here on this forum. I'll be interested to see the responses as I'll be working on some exteriors too. |
Bo Atkinson (boa)
| | Posted on Sunday, October 28, 2001 - 07:19 am: |
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IMHO, for fast, effective rendering of complex concrete form work, use the new "woven" reflection set to rough. Choose your simple color tint(s). Turn off extra rendering options. Like turn off smooth shade on rectilinear forms, but perhaps turn on smooth shading for well rounded forms. Perhaps use slight color tint variations for different forms depending on position or floor level. Render speed is very fast now.... Most likely turn off shadows and add your own large shadow areas in photoshop where you can visually control with masks. The idea of rigidly modeling lighting effects seems to deny the reality that the human perception is not static, but rather a collective experience, more like snapshots. Therefore idealized and simplified lighting can better reveal the essential architecture, leaving the effects to choreographers. The idea of getting perfect model renderings in one shot feels a bit too much like building ships inside bottles. I'd rather build a real ship and sail away ;) Of course i'd take Z with me, always!
The growing options of rendering are interesting, but non visual tweaking does seem very time consuming when it comes to deadlines, (normal life). I too look forward to yet more opinions to learn from here! |
Josephus Holt (holtj)
| | Posted on Sunday, October 28, 2001 - 04:21 pm: |
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John, I don't know if this will help, but here's a tip I received for adding indirect lighting for interiors, and may apply to your situation as well. First of all, I also set ambient lighting to zero, and first tried using distant lights perpendicular to the surface that needed indirect or fill illumination. The effect is rather flat and will include all surfaces that are directly perpendicular to the distant light direction. I was advised to use cones with square falloff instead, turn off shadows, and make them very small, like with a 12" or so distance from "location" to "center of interest" aimed a few degrees off perpendicular to the surface where you want bounced/fill light. Color it a little lighter than the material/surface the light is supposed to bounce off. The light intensity falloff begins at the end of the cone, and once you get a feel for the best distance the spotlight should be from the surface, and with that distance what the (simple) illumination intensity should be, you'll be able then to quickly add others. It gives a real nice soft bounced light look. I just learned recently that lights that don't cast shadows go right through walls, roofs, etc. For key (direct) lights I was advised to use hard ray-traced cones and for indirect to use cones with no shadows or with soft-mapped shadows (would have to be inside the model) and point lights with no shadows. I've found when trying to render out large images that had multiple point lights w/soft mapped shadows that my machine w/448mb ram would not render the shadows as the shadow maps became too large. Is this any help to you? |
Panos Zervos (panosclip)
| | Posted on Monday, October 29, 2001 - 03:45 am: |
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From my experience, though I' m not an architect, in exterior lighting I would use about 10% to 20% ambient light but in a medium bluish (not very saturated) tone (just about the sky's colour). This helps shadows get tinted a bit.
As for the directional (fill) lights, don't place them perpendicular, use an 80 -85 degrees angle and a very low intensity with a slight yellow or green tint. First choose position, colour and intensity for your "sun" and then mirror/copy this light at 30% of intensity and colour. I would mirror it so it lights from back and under the scene, as this gives the impression of scattered sunlight. All other lights depend on your view. Post a rough image of what you are looking for, so we could give you more specific advice.
Mr Birn gives us some basic rules on lighting which apply in most conditions. This does not mean that we are obliged to follow them, with eyes closed.
Hope this helps,
Panos Zervos |
support@formZ (tech)
| | Posted on Monday, October 29, 2001 - 10:13 am: |
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John et al,
The subject of basic lighting has come up many times before and we have suggested a basic scheme of 4 distant lights that can be used as a starting point for lighting a scene. These basic lights are included in the file below, along with a simple object to illustrate the effects.
Note that the intensities of these lights is set so that these lights can be used alone. Additional point or cone lights can be added for more "variety" of lighting in the scene. In this case, the intensity of these lights should be reduced to allow the other lights to show their effects - without washing out the scene.
Hope this helps,
ZWebTech Support |
John Cassel (cassel)
| | Posted on Tuesday, October 30, 2001 - 04:55 am: |
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Josephus, Bo, Panos, ZWebTech,
Thank you all for the help and tips.
I've just tried the lights that ZWebTech posted above and found them to be a great starting place for general lighting. It is a real confidance booster to see how others create lighting for models. I'll be using these lights in my models until I learn a bit more.
I went ahead and ordered Jeremy Birn's book. I had a look at a copy and it looks like a good solid place to start.
I also had a look at the Arnold Gallardo's 3D Lighting: History, Concepts, and Techniques published by Charles River Media. There is probably a lot of great information in there too. Unfortunatly, Charles River has decided to publish it in black and white making it harder to get an easy grasp of the information presented. IMHO it is odd to publish a book on digital lighting in black and white.
Thank you,
John |
Jim Pomy (jim)
| | Posted on Friday, November 09, 2001 - 09:31 am: |
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I am trying to study the natural daylighting in a building design modeled in FZ. I have had success in lighting the model for purely presentation purposes but, as I said, now I want to actually study the daylighting characteristics of the interiors...without any artifical light sources. Any recommendations of how to accomplish this? Light settings? Placement? Number of lights?(though it seems this should be 1...the sun. |
support@formZ (tech)
| | Posted on Friday, November 09, 2001 - 10:28 am: |
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Jim,
As light from the sun nears the earth it gets bounced around by all the molecules in the atmosphere. This produces an indirect "atmospheric light" that allows the side of your building that is away from the sun to still receive some light. Therefore you might want to set your sunlight to Accurate and turn on the Apply Atmospheric Light settings. You can set the intensities to:
Accurate intensity, .08 Watts / sq. ft, and
Sky Luminance = 6 Candelas / sq. ft.
Note that the default values for the Quality slider are way too high for versions prior to 4.0. You probably want it set somewhere between 1/8th and 1/4th of an inch from the left. For version 4.0 and later, this slider has been adjusted, and 50% or less is fine for a test rendering, but you might want to set it to 100% for a nice, final rendering.
There is a good discussion about Atmospheric lighting on the forum, which you can find if you use the Keyword Search (from the left) and search for atmospheric.
Additionally, as the light enters a window or skylight, it will hit a wall or the floor. This surface will essentially become a secondary light source, which will bounce light to illuminate other surfaces in your scene. In order to see this bounced light, you will need to generate a Radiosity solution. See the manuals and do a Keyword Search for radiozity.
To optimize the RadioZity Solution, you will need to make sure to turn off the RadioZity Meshing for all of the exterior surfaces. This will cause the solution to focus on the interior surfaces, where it seems you are most interested. Further optimizing can be accomplished by "pre-meshing" the interior surfaces - especially those that receive direct sunlight.
While both of these techniques together should give you what you are looking for, they are both very computationally intensive operations. Together they will take even more time and memory than they would alone. Therefore, to achieve your rendering in a reasonable amount of time, you may want to approximate the atmospheric lighting. Probably the best way to do this would be to place a light meter at a window that faces the same direction as the windows in your model, and measure the light intensity coming from the windows at the desired time of day. Then you can place CONE lights at each window to simulate the exterior reflected light. This will then make your RadioZity solution even more efficient (as it will not have to deal with all of the light bouncing around outside your building).
Hope this helps,
ZWebTech Support |
Jeff Grunewald
New member
Username: Jeffg
Post Number: 7
Registered: 06-2002
| | Posted on Wednesday, March 28, 2007 - 05:37 pm: |
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I've discovered the beauties of Environmental lights in a recent architectural project. I'd suggest Environmental lighting to fill in shadows realistically. It can look like Ambient Occlusion in some areas, such as under eaves. If you don't have a photo to use for the scene, you can make a set of HDRI files that can be used in a cubic lighting scheme. Make the top plane like a sky with a bright spot for the sun and the side planes simple gradients of colors you would expect to find in nature. Save them in Photoshop CS2 as 32 bit Radiance (hdr) files. You can also use Spherical mapping on the Environmental light, which requires only one image, but it didn't give me the same control as the 6 part cubic map. Start testing renders with low numbers of samples before bumping them up to 300+. I had good enough results with 150 samples on a distant scene. Close-ups will require more samples.
FormZ 6.5 will have Ambient Occlusion and Global Illumination but Environmental lights can render faster. |
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lighting