PDA

View Full Version : Help with workflow...


3drocket
04-23-2009, 07:47 AM
I am interested in getting some feedback/suggestions on my Mudbox work flow.

For the project I am working on the final output is for a real time simulation being created in the OGRE engine.
The camera in OGRE needs to get extremely close to the models surface so we desire maximum detail in the model.
Through trial and error we have found that around 300 thousand poly’s is about as much as we can use in OGRE with the shaders we are using and still get the frame rate high enough.

Here’s the process I have followed so far....

1. Created a single base mesh in max that was all quads and made to match the final models form as closley as possible at this stage in the process. The base mesh has 24 thousand quads. The model has a complex organic form it needs to follow.

2. UV mapped the mesh giving it five maps to cover its surface with lots of texture detail.

4. Exported the mesh as an OBJ file and imported into Mudbox.

5. Sub-divided, sculpted and painted the mesh in Mudbox. The highest level is 5 and it has 12.6 million quads.

6. I exported a level 3 mesh as an OBJ and took it back into max. This model had 1.5 million quads

7. I baked out the Normal maps using the original base mesh and the level 5 sculpting.

8. In max I applied a ProOptimizer modifier and left it overnight (takes hours on a large mesh) to calculate the optimization.

9. Using the ProOptermizer I reduced the poly count down to the desired 300 thousand polys. The form of the model looked great and is no longer quads.

10. Assigned a material with five sub object materials and loaded all the maps that were painted in Mudbox.

11. Exported the model to OGRE. The export is an overnight job as it is very slow even on a good workstation (Dual quad core Xeon + 16gb ram).

The model comes into OGRE with some very noticeable problems (See attached image).
I think the dark spots may be caused by using an incorrect search distance when exporting the normal maps.

I tried taking the optimized mesh back into my Mudbox scene and even though it will load with the non quad warning it will hang when using it as the low res mesh when I try to bake out the normals.

I am wondering if I will get a better result if I create a new 300 thousand poly mesh based on my high poly Mudbox mesh using a tool like Topogun rather than using the ProOptermizer modifier in max.

quyeno
04-23-2009, 09:44 AM
your workflow seems fine dude. those artefacts looks like a cage problem. in my experience its not search distance but rather a weird vert problem which causes the verts of the cage in those areas to move inwards rather than outwards when you increase the search distance. for me, it was due to the verts not welded. so basically try welding the verts around there, also check for overlapping polys (poss from the optimise). also triangluate around that area. if you can;t be bothered rebaking, you could clone it out in photoshop using a soft brush or paint it out using a purple colour around that area.

Wayne
04-23-2009, 11:03 AM
Yes it looks like an intepenertration issue with the cage. One work around is to generate one map where those parts are fine and the rest of the map is FUBAR, and one such as you have and then add both to a plane as texture layers and erase the unneeded bits.


Wayne...

3drocket
04-23-2009, 01:13 PM
Thanks guys for the advice. :-)
Really appreciate it.

I noticed tonight that I had "Smooth Target Model" on and that was having a big effect on the quality of the Normal map. I will have a look in max for any verts that are not welded.

Is there an easy way to apply the sculpting I have done to the model if I change it in max?

Wayne
04-23-2009, 01:52 PM
Thanks guys for the advice. :-)


Is there an easy way to apply the sculpting I have done to the model if I change it in max?

Bake the details from you changed low res fro your high res by importing your high res and new low res nto a scene and creating a disp map 32 bit openEXR works well. The you can ue sculpt using displacement to get your details back. If ther are surfaces very close to each other, you may need to do some clean up dependig on the sculpt and base geo.


Wayne...

3drocket
04-24-2009, 12:27 PM
Thanks Wayne I will give it a try this weekend.