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Filmdesigner
08-10-2006, 02:23 AM
I am not very good at rendering interior scenes. I am looking for some "how to's" from my esteemed collegues and fellow lightwavers.

Radiosity or light rig set-ups and render parameters would be useful.

Cheers, Phil

dablan
08-10-2006, 09:20 AM
Hey Phil,
for interiors, can lights (spots) always work well. This gives that recessed lighting look.

For radiosity (indirect illumination) do not rely only on this. In LightWave, radiosity works best in conjunction with other lights. Use the radiosity to help "fill" the indirect areas of the scene. Area lights work well as soft interior light sources.

MooseDog
08-10-2006, 09:38 AM
Daylight Setup with Radiosity Added (http://www.spinquad.com/forums/showthread.php?t=8388)

as dablan noted, g.i. is your helper, not your saviour.

Filmdesigner
08-10-2006, 08:46 PM
Sorry guys! (Hey Dan, love your books!) I should have been more specific. There are certain particular tricks to achieving a quality render instead of a flat or washed-out render. I have the tendency to light my interior to suit the film work I do, which is moody and dramatic. I am having trouble achieving an "advertising" feel, if you know what I mean.

I will post an image in the "Work in progress" section.

Thanks, Phil

dablan
08-10-2006, 09:00 PM
Glad to hear that! Thanks.

The interiors I've done, I bring down the ambient to almost nothing. I add lights as needed. Often, a mix of area, point, and spot. And as mentioned here, use a little radiosity to fill the indirect areas. Simply, setup the interior lighting as if it were a real set. That is, if your model has 10 can lights in the ceiling, add 10 spotlights in those spaces. Set the soft edge angle high for it's a nice falloff. Change the color to match the type of lighting, perhaps incandescent. Then, work with the intensitity of those lights so the shot looks right. Add additional lights to fill in lamps, tracks, etc. Add an area light to replace outdoor light coming through a window, etc.

The shots attached:
The interior airplane shot was lit without radiosity. There are area lights, about three on each side of the plane, set to a very high intensity. The diffuse values of the seats are set low to compensate for the high intensity light. The area light also had a inverse distance falloff set so the light diminishes toward the isle. There are linear lights around the overheads to light above the seats.

The sink shot uses a spotlight with a projection image of a black and white window frame blurred. The color was set to and off white, slightly orange to give a sunlight look. A small point light is added to the left of the scene as a fill.

The schoolhouse shot, although about 6 years old now, uses all spotlights and point lights. Some were set to a soft blue to simulate night time, and a warmer one was used for the candle light. There's a large, spread wide spot in the ceiling to light the room, but very little - about 10 - 15%. Mostly this light is to cast shadows. Today, I'd use area lights instead, and a little radiosity. Back in '99 this could only be done with spots due to render times and deadlines.

Hope that helps!

otacon
08-10-2006, 09:49 PM
I agree with Dan, radiosity should be used mainly as filler to help you with those second and third bounces. As for what kind of lighting you should use, that depends on what you need to do. If you only need a still render, i would use radiosity with fprime almost every time. If you need to render out an animation, you might be better faking radiosity with regular lights. It will take more time to setup, but in the end you will get faster render times.

The two images attached here are pretty similar in look, yet one was rendered with radiosity, and one without. Most cg artists could tell the difference, but most clients could not.

For the non-radiosity render i used lots of point lights and a few spotlights, almost all of which have shadows turned off and are using linear falloff. It was for an animation, so i needed quick render times. There is only one light in the scene with raytrace shadows and that is the sun. Here's a tip that you don't hear very often, use negative values on your light intensities to fake shadows! It's a very quick and easy way to control the ambient light in your scene. Also, it's important to color your lights. I never use white lights, every light should have some color to it. This also plays a big part in the feel of the render. Before you even start to light your scene you need to think about what the main source of light is going to be. Start from black and start adding your lights one by one, starting with the lights that are most intense.

Those are just a few of tips i have. Another big thing is practice, the more you work at it the more secrets you start to learn.

dablan
08-10-2006, 09:58 PM
Nice work there Otacon!

archiea
08-10-2006, 10:31 PM
have you guys thought of using the new occlusion shadersin LW to help simulate the radiocity? You can render an occlusion shader applied to everything that will shadow the areas of surfaces that touch. Save it as a bitmapped and then take your final render with keys and fills (no radiocity) and multiply it against you occlusion render in photoshop or something. The corners in your scene will get darker, thus eliminating what radiocity would do as light is bounced and eventually diccipated in dark corners. However, you willlose the bounce tht you get from radiocity.. however that is what your (many) bounce lights are for...

While side by side, an occlusion shader solution will probably look inferior to a radiosity (pver generalizing here), it wlll usually look better than a straight non radiosity render.

kewl example from the mental ray folks. Sorry its max. I should get off my *** and make a page like that for LW...
http://www.everflow.com/support/tutorials/AO/Everflow_AmbientOcclusion1.html

some ambient occlusion primer stuff..
http://www-viz.tamu.edu/students/bmoyer/617/ambocc/
http://en.wikipedia.org/wiki/Ambient_occlusion
http://www.cs.unc.edu/~coombe/research/ao/
http://www.christopher-thomas.net/pages/free_tutorials/tut_ambient_occlusion_shader/ct_tut_mentalray_ambientocclusion_shader.htm

prayforjoejoe
11-15-2006, 01:31 PM
Hey dan! Whats up with the site? I always get problems trying to access 3dgarage. Love the books!

dablan
11-15-2006, 01:36 PM
Nothings wrong with the site. Works in all browsers.
When did you last visit? Might need to refresh your cache... or empty it.

Yep - it loads fine. Just checked. Refresh your browser.

Filmdesigner
12-01-2006, 02:23 PM
Thanks for the advice. I have been playing with your suggestions and will post some results shortly.

Thanks all.

ingo
12-02-2006, 02:35 AM
have you guys thought of using the new occlusion shadersin LW to help simulate the radiocity? ....

Or the old 3rd party occlusion shader ?? Here is an example of an interior rendering with occlusion without raydiosity. For more look on my website http://www.im-graphics.de/p/ve.html and look for the project "Renovation office building Siemens Berlin" , its the 9th one from top.