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 following paragraphs.
3.0 Tools Used:
Before i will start showing you the workflow i used for Varga i will summarize the tools i used for this project.
First let me summarize the specs of the pc i worked on because most of the limitations i encountered on the way were hardware dependent:
- athlon xp 2500+ @2400 ( but overclocking won't do much good on this old machine :) )
- 1GB of RAM
- video GeForce 6600GT
You can probably guess that this is no high-end machine and i was way limited to the number of polygons i could use at the same time ( in mudbox i could go as high as 2mil triangles but it will move too slow ), in maya i had a lot of crashes when trying to import obj files bigger than 1.5 mil tris ( not enough ram) and i tried to break down the model into pieces (head, torso, hips, legs , arms etc) so i can achieve enough polygons to sculpt the details i wanted without crashes or unmanageable scenes ( usually the polycount per piece will not exceed 1mil tris ).
Regarding the software used ,I am mainly a maya user so lot of the work was done in maya ( modeling , uvs , texture baking , rendering ).
For high rez sculpting i used mudbox ( build a low cage inside maya and export it to mudbox for further detailing ).After the sculpting part is done i will export one of the higher level as an obj file ( usually a 100-300k tris mesh worked fine at this stage , no need to export the highes level ) and import it in topogun along with a low poly cage ( if i already have one , or build a new one from zero within topogun)and rebuild the topology to better match the details i have added to the high rez mesh.After this process was done i will import back into maya the low and high versions and compute the normal maps with transfer maps tool.
The normal maps were further tweaked within photoshop;some were done completely in photoshop ( check the maps for Peril- the bow later on ).
After all this chit-chat let me show you some wip images in the following paragraph.
4.0 Workflow used for Vatga:
Usually for game characters you will have some specs to follow : limit to the number of triangles , size and numbers of textures used; you will have to conform with the number/size of the textures but if you exceed the polycount by 500 - 1000tris ( lets say for 8k budget ) and the character is looking cool ... it's less likely the client will be mad :).
For this competition the limit was 6000 tris and i wouldn't want to exceed that so the first step was to build a low poly cage to allot the polygons between all the assets (the main char , pet , weapon ) , it doesn't have to be final but to let me see what details i can incorporate into the high version.
4.01 Low Ploy Cage:
Below is a guick timelapse with the first low poly versions (the triangulated one is the final version though)