Making of Varga by Paul Tosca, Romania Web: www.paultosca.com

The second approach for modeling : high poly/low poly/uvs /textures will give you the freedom to start sculpting and adding details from the beginning and you will get rid of the problem stated above also. However ,when modeling the high version first you have to keep in mind that this will be used to bake normals for a low poly cage and model it accordingly.

You will have to estimate what details worth adding and that could be used properly when computing the normal map for the low poly version. For instance if i will have the high poly below:

...I could use a single quad plane for the low poly but the result will not represent the high version very good.

When viewed from above they seem too look identical.

but when viewed at slanted angle you can see that the single guad plane does poor in reproducing the high detail

a better approach is to spend a couple more polygons to make the low poly better match the high version

then the low poly with normal map will look better viewed at slanted angles (of course ,depending on the polygon budged you could add more geometry to get rid of the rugged look)

Also,you have to avoid modeling complicated shape details that will be hard to enclose within a low poly cage later on because they will "eat" too many polygons to be displayed properly, though you might be tempted to go crazy and add lots of detail like shown below.

The high res model might look nice but when building the low version on top of high you will always have to stay within a polygon budget (5-10k triangles or whatever) and if you did not plan high poly details in advance you might face the situation where you will need more polygons than alloted to better match the already high model, and you will have to go back and change the high version. But with some practice you will know what detail worth incorporating in the high version and what details to miss because will be hard to reproduce.

Another big advantage of the last workflow is that you could also bake an ambient occlusion map and other maps (a simple diffuse pass or even specular passes to give more variation to the textures) using the detail from the high poly model and you could use them as a starting point for the textures.

Also you could try a combination of the two methods shown above, in fact this is what i have done for Varga and i will show you later on in the upcoming paragraphs.