Tuesday, April 2, 2013

Day 202

I said before the egg model had about 1.5 million polygons and the file size was 200 mb which is kind of overkill. Unless it's used to render still images like in an ad or something, this egg isn't too useful as it is now. Another thing Mudbox can do is output different kinds of maps. One is a texture map which is all the color that I painted. On the left I have a low rez version of the egg which I've opened up in Maya. On the right is the same egg with the texture map I made in Mudbox applied onto it. This is a much easier method compared to painting things in Photoshop.

Another kind of map Mudbox can make is called a displacement map. Mudbox looks at the surface of the million polygon egg and see where all the bumps and pit are and records this information in the form of a black and white map. I can now take this map and apply it to the low rez egg in the Maya and I end up with the egg on top left. The displacement map actually changes the geometry of the egg but only at the time of rendering. Before then, the egg is quick and easy to manipulate and doesn't use up a lot of processing power. So there's no slow down while working with the egg but rendering takes awhile. To speed things up even more, we can make a normal map. Normals are lines that are perpendicular to the surface of the model. Mudbox records this information as a colored map. When applying this map onto the low rez egg, Maya will use this information to figure out how light should bounce off the surface. The geometry doesn't actually change so this is a way to fake the extra detail and doesn't require a lot of computing power especially compared to a displacement map.  

Above is a picture of the two maps. Since I just made little bumps and pits on the egg, you don't really see much. I had to zoom in a lot of the maps for you to even see a little bit. If this is confusing, I did the same thing awhile ago on this blog and it may be easier to visualize. Below is a picture from that post. On the left is the high rez frog with which a normal map is generated. In the middle is the low rez version which the map will get applied to. On the right you see the final result. I said normal maps don't actually change the geometry of the model. So the model on the right has the same silhouette as the low rez version (because it is the low rez version with just a map applied). The end result is a detailed looking model that has a low polygon count and will be easy for a computer to process.

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