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lisa · 1st August 2007, 07:06 PM

Sure thing!

Here is a very good tutorial on normal mapping, with lots of pictures plus a simple shader implementation. This should give you a clear, visual example of how altering the surface normals changes the perception of the shape--without changing the geometry:
http://www.bencloward.com/tutorials_normal_maps6.shtml

Tip: If you want to use AC3D to make normal maps from high-resolution models and you use POVRay as your default renderer, you'll want to download MegaPOV and use it instead. MegaPOV will let you render normals as a pigment, but the "official" POVRay build won't (yet).

These links are a bit old, but they are a very straight-forward explanation of imposter rendering. The first link has a video so you can see it in action:
http://www.markmark.net/clouds/
http://www.gamasutra.com/features/20...davis_01.shtml

Good video tutorial explaining LOD. This is Maya-specific, but the concepts are the same regardless of which renderer you are using:
http://www.digitaltutors.com/digital...ails.php?v=895

The type of LOD shown in the tutorial is called "discrete LOD". There are other types, such as CLOD and progressive meshes, but DLOD is most commonly used--especially in games--because it is easy to implement and *much* less computationally expensive than other methods. DLOD usually causes a small amount of "popping" as you switch between meshes, which is why other methods exist, but if you tune your scene right the popping is usually not noticable.

If you have questions on the specifics of any of these, ask away.

I've had my hands under the hood of quite a few game engines over the years, so I've implemented all of these at one point or another.

1st August 2007, 07:06 PM	#6
lisa Senior Member Professional user Join Date: Mar 2005 Location: Phoenix, AZ Posts: 917	Re: Professional polycount. Sure thing! Here is a very good tutorial on normal mapping, with lots of pictures plus a simple shader implementation. This should give you a clear, visual example of how altering the surface normals changes the perception of the shape--without changing the geometry: http://www.bencloward.com/tutorials_normal_maps6.shtml Tip: If you want to use AC3D to make normal maps from high-resolution models and you use POVRay as your default renderer, you'll want to download MegaPOV and use it instead. MegaPOV will let you render normals as a pigment, but the "official" POVRay build won't (yet). These links are a bit old, but they are a very straight-forward explanation of imposter rendering. The first link has a video so you can see it in action: http://www.markmark.net/clouds/ http://www.gamasutra.com/features/20...davis_01.shtml Good video tutorial explaining LOD. This is Maya-specific, but the concepts are the same regardless of which renderer you are using: http://www.digitaltutors.com/digital...ails.php?v=895 The type of LOD shown in the tutorial is called "discrete LOD". There are other types, such as CLOD and progressive meshes, but DLOD is most commonly used--especially in games--because it is easy to implement and much less computationally expensive than other methods. DLOD usually causes a small amount of "popping" as you switch between meshes, which is why other methods exist, but if you tune your scene right the popping is usually not noticable. If you have questions on the specifics of any of these, ask away. I've had my hands under the hood of quite a few game engines over the years, so I've implemented all of these at one point or another.