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Teyon · 26th May 2006, 08:03

Put simply, you want your UVMaps to be as flat as possible, which translates to as evenly laid down as possible. To achieve this in Hexagon you should attempt to cut your model into logical sections that will be easy to manipulate. For example, if you are UVMapping a human and want the least amount of seams on the model, you'd want to go for a "pelt" like map style. Pelting is when you take the skin of an animal and stretch it in several directions until it lays flat...this same thinking would be used in making your UVMap. A great example of how you could achieve this using the same techniques required for Hexagon would be to follow the tutorial found HERE.

Take a long look at the first image on that page. See the green lines on the model? Those are the seams or "cuts" that the person ended up with. It isn't 100% the way I cut my models, as each model should be handled differently but it is a good general starting point. Read through the tutorial, you'll begin to see some of the logic behind this type of UVMapping. At the end of the day though, it's up to you to decide how best to cut your model to get the most out of the texture space. For example: UVMapping for a videogame character is different than UVMapping for film or stills. So are the texturing processes. So also keep in mind what your end result will be used for.

In games, it's not uncommon to lay similar UV's on top of each other to maximize the limited UV Space (most game models have a max UV res of 1024x1024 with more common maps in the 256 and 512 range). So game model UV's tend to have things like hands on top of hands and feet on top of feet, anything to get the most bang for the small space allowed.

Film and stills tend to have a more pelt like approach, where the entire UV is laid out in a skinned kind of way. This allows for asymmetry in the texture, which is important for adding realisim to a model. However, because the model is mapped as mostly a single object, larger resolutions are needed for more texture information to get on each poly (remember, the UV's are a MAP for the texture). Thus most film characters start out using at least a 4096x4096 map, with some going as high as 8000 for extreme close-ups required in shots. For mid range or background characters, 2048x2048 is acceptable but they still don't hold up as well as they could in close-up view. All this info I just blurted should be considered briefly when making your maps. How big will you need the final texture to be? Will the character be the center of attention in the image or a background element? These things will determine how much you can get away with in your maps and what parts may need their own areas in UVSpace.

Take a look at the image in this post. I've labeled the parts of the map. This kind of map would be good for a video game character or a character in a film. It lends itself to both, since every part is on the same UVMap. Sometimes in film, you need to break your models into multiple UVMaps, again to maximize the amount of detail. Let's say you wanted to make a digital duplicate of one of the film's actors that had to pass in front of the camera briefly. For this, you'd want a 8000x8000 map for each body part, which would allow for the most detail. However, such a map isn't practical for everyday creation and isn't really reccomended for use in Hexagon, as it tends to prefer single maps like the one shown.

Now just to keep this train running on my hot air, this model was sliced and diced to allow all the seams to be in hard to reach places like the inner thign/crotch area for the legs, the armpit area for the arms, the back area for the torso. In Hex, it's a little easier to ufold things though I find working in the way described in the WINGS tutorial is probably the best method for characters, as it allows more control. Also keep in mind that one of the programmers was a bit daft and made Hex flip the textures on export, regardless of how it's mapped in the program, so you'll have to flip things back once you're out of Hex. Simple to fix but we really should never have had to in the first place. Bad Eovia! Bad! No dinner for you!

I hope this long winded, self-involved post helped you to understand the thought process behind UVMapping characters, UVMapping in general and UVMapping in Hex specifically. I know it's not perfect and sure as heck ain't a tutorial propper but it's all I have time for.

Here's the same model in Headus UVLAYOUT, so you can see the seam's placement.

26th May 2006, 08:03	#24 (permalink)
Teyon Go Team Venture! Join Date: Jul 2005 Posts: 186	Put simply, you want your UVMaps to be as flat as possible, which translates to as evenly laid down as possible. To achieve this in Hexagon you should attempt to cut your model into logical sections that will be easy to manipulate. For example, if you are UVMapping a human and want the least amount of seams on the model, you'd want to go for a "pelt" like map style. Pelting is when you take the skin of an animal and stretch it in several directions until it lays flat...this same thinking would be used in making your UVMap. A great example of how you could achieve this using the same techniques required for Hexagon would be to follow the tutorial found HERE. Take a long look at the first image on that page. See the green lines on the model? Those are the seams or "cuts" that the person ended up with. It isn't 100% the way I cut my models, as each model should be handled differently but it is a good general starting point. Read through the tutorial, you'll begin to see some of the logic behind this type of UVMapping. At the end of the day though, it's up to you to decide how best to cut your model to get the most out of the texture space. For example: UVMapping for a videogame character is different than UVMapping for film or stills. So are the texturing processes. So also keep in mind what your end result will be used for. In games, it's not uncommon to lay similar UV's on top of each other to maximize the limited UV Space (most game models have a max UV res of 1024x1024 with more common maps in the 256 and 512 range). So game model UV's tend to have things like hands on top of hands and feet on top of feet, anything to get the most bang for the small space allowed. Film and stills tend to have a more pelt like approach, where the entire UV is laid out in a skinned kind of way. This allows for asymmetry in the texture, which is important for adding realisim to a model. However, because the model is mapped as mostly a single object, larger resolutions are needed for more texture information to get on each poly (remember, the UV's are a MAP for the texture). Thus most film characters start out using at least a 4096x4096 map, with some going as high as 8000 for extreme close-ups required in shots. For mid range or background characters, 2048x2048 is acceptable but they still don't hold up as well as they could in close-up view. All this info I just blurted should be considered briefly when making your maps. How big will you need the final texture to be? Will the character be the center of attention in the image or a background element? These things will determine how much you can get away with in your maps and what parts may need their own areas in UVSpace. Take a look at the image in this post. I've labeled the parts of the map. This kind of map would be good for a video game character or a character in a film. It lends itself to both, since every part is on the same UVMap. Sometimes in film, you need to break your models into multiple UVMaps, again to maximize the amount of detail. Let's say you wanted to make a digital duplicate of one of the film's actors that had to pass in front of the camera briefly. For this, you'd want a 8000x8000 map for each body part, which would allow for the most detail. However, such a map isn't practical for everyday creation and isn't really reccomended for use in Hexagon, as it tends to prefer single maps like the one shown. Now just to keep this train running on my hot air, this model was sliced and diced to allow all the seams to be in hard to reach places like the inner thign/crotch area for the legs, the armpit area for the arms, the back area for the torso. In Hex, it's a little easier to ufold things though I find working in the way described in the WINGS tutorial is probably the best method for characters, as it allows more control. Also keep in mind that one of the programmers was a bit daft and made Hex flip the textures on export, regardless of how it's mapped in the program, so you'll have to flip things back once you're out of Hex. Simple to fix but we really should never have had to in the first place. Bad Eovia! Bad! No dinner for you! I hope this long winded, self-involved post helped you to understand the thought process behind UVMapping characters, UVMapping in general and UVMapping in Hex specifically. I know it's not perfect and sure as heck ain't a tutorial propper but it's all I have time for. Here's the same model in Headus UVLAYOUT, so you can see the seam's placement.