Thread: i need help :(
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# 4 29-09-2010 , 11:43 PM
Nilla's Avatar
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Join Date: Jun 2009
Location: Prague
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Hi Sam,

To get very good results with the scenes you have is quite difficult as you have multiple objects and the lighting of the room they're in to worry about in addition to this. I personallly think it's a bit much to take on for someone who's new to this, and I don't understand why your university would give you such a complicated project with no additional information, because I've been doing lighting and shading in Maya for two years and I struggle to get something like this to look good. But if you have a bit of time to complete this it should be possible to do, I'm working with scenes similar to yours at the moment for our more complicated lighting tutorials so if you want I can help you along the way because I love this topic.

You need to start by breaking things down and working on the individual objects, also you need to learn the lighting and shading separately and when you have the basics for both you can start to bring them together and work on your scene as a whole.

I'm gonna start by going over the shading, and first of all there's nothing in your scenes that will require UV layout so don't waste your time on this because it takes ages and it's not the most interesting thing either. You want to focus on using the shaders Blinn, Phong, Phong E, Anisotropic and Lambert to create things like plastic, metals, porcelain and wood. By connecting in Maya's procedural 3d textures to different attributes of these shaders you can break things up and get variations like scratches on a plate, these textures work independent of UV's on geometry and should be used for basic hard surface objects. I've just finished a tutorial on this, two of the parts will be in the free section tomorrow. One is an introduction to lighting and shading that goes over the very basics, the second one shows you how to create porcelain and plastic materials so watch these to start somewhere.

I create materials in isolation with a lighting dome because this is a quick way to get some good overall illumination and see what things look like, there's a tutorial in the free section on how to set up a basic dome, remember that almost all materials have some sort of specular highlight even a rough surface like rubber and these will not show with indirect illumination only so you will need a spotlight to boost these kind of highlights.

When it comes to creating polished metals we were just talking about this in a different thread https://srv01.simply3dworld.com/showt...hreadid=34446, if you read what is in there it should give you the fundamentals to make any kind of metal you might need along the way.

Glass is easy to make with mental rays dielectric material at default settings, as with metals keep in mind that glass surfaces are highly reflective so the quality of something like this comes down to what's in your scene to reflect. Getting really good looking glass is very difficult.

For wood, I uploaded two shaders to the resources section of the site a few weeks back you can get them here https://www.simply3dworld.com/downloa...eid=5&catid=16 and import them into your own scenes. If you look at the networks for these it will give you a good idea of how to connect things together in terms of different materials. Dave also made a burnished copper which is really nice. You can find a lot of additional shaders on highend3d, but they are of variable quality and a lot of them have very complicated shading networks with utility nodes that you'd need to understand.

When you have some general base materials to work with you can start to assign these to the objects in your scene, and at this point you will have to tweak them to work with the lighting set up you have. This is the point where things get difficult because to work with so many different materials and getting them all to look good will require a lot of knowledge on lighting in terms of that a light set up that works well with some materials might not work so well with others. This is the reason for why when you see tutorials on environment lighting they'll use a room with very few objects in it, I'm working on a tutorial right now covering lighting for different times of the day and there's almost nothing in my room.

Indirect illumination with final gather, gi and physical sky and sun are the best methods for lighting interiors and exteriors and the way to go when you have different materials like this, but all these things are very complicated topics. Because you need to do a lot of test rendering when you light complete scenes like this to get a good end result it is really important to understand the technical aspect of how these features work as it will take a long time to render with them. If you know how to tweak your settings this can be the difference between a render time of five minutes as opposed to one hour, and if you have to make 50 test renders during the lighting and shading process to get to the result you want this will make a huge difference. A quick and dirty way to get some good overall illumination into a room would be to scale up a volume light and turn on final gather to get the indirect illumination from this. If you scale it right you'll also get darkening that will naturally occur in the corners of a room.


For mental ray itself as a renderer Sybex has a good book on the more technical side that you could take a look at. David's also doing some tutorials on this for the site, they'll be done in a few weeks and he's put lots of time into them so they're were high quality tutorials in terms of content. If he can get the recording to come out well without sounding like a muppet is a different storyuser added image

If you want you can send us your scenes nilla@simply3dworld.com and me and David can have a crack at it and probably help you get started on things.

Best of luck,
Nilla