Voxels to mesh - how to keep details and workflow request.

[simmsimaging]

I am still waiting for some further help sorting out getting displacement/normal maps out of 3DC, but in the interim decided to have another crack at doing the detailing via voxels.

I'm hit a fairly good level of fine detail, but now I can't figure out how to keep that when converting to a mesh.

Attached are two screens shots - one is the voxel sculpt (just a test for now, but has some very fine line detail on one part). The other is the mesh in paint room with a (more or less) default export via "quandragulate and paint" from the right-click voxel tree menu).

Clearly it's a mess - all the really fine detail is totally lost, but even the basic geometry is torched. How do you actually go about doing this? All the numbers you can enter in the dialog boxes during the process seem to be basically meaningless in terms of the actual model generated, and I can't figure out what more to do with them. Testing is taking forever because the 'quad and paint' process takes about 10 minutes every time I try - and there is only so much time in a day....

Is there a clear, simple (or at least consistent) workflow for taking a model like this out of voxels and into a mesh with normal and/or displacement mapping? Is this something that needs to be done with the Texture Baking tool or something?

Thanks in advance

b

[philnolan3d]

I'm not sure what exactly went wrong but for one thing guadrangulating doesn't really handle sharp edges very well most of the time. This is a case where you're better off doing the retopology yourself and merging to the painting room from there.

Here I've made a sample sculpture with some fine detail as well as sharp edges:

I retopo'd it and merged for Per Pixel Painting using these options

And here it is in the painting room. 96 polygons and one 4096 size texture:

Here's object if you'd like to have a look at it:

http://rapidshare.com/files/341743510/detail_test.zip.html

[splodge]

Simms, your resulting model looks strange and faceted. It shouldn't be that bad after quadrangulation.

But like Phil says - quadrangulate doesn't capture sharp edges. I personally don't use quadragulate any more and instead I export a low poly version my voxel model and then switch to Retopo and import the mesh back in (Retopo/Import). I then bake the details of the voxel model onto the low poly mesh (Retopo/Merge for pixel painting with normal map).

[splodge]

Here's my 2000 triangles shield that was made in no time (No retopology necessary):

[simmsimaging]

I'm not sure what exactly went wrong but for one thing guadrangulating doesn't really handle sharp edges very well most of the time. This is a case where you're better off doing the retopology yourself and merging to the painting room from there.

Thanks Phil. I was able to get a somewhat better mesh via 'quadrangulate and export' but I had to make a lot of tests and guesswork at the mesh values. In your example you have set the poly count to 6.85 million - how did you arrive at that number?

I'm still not sure what that number really means, and your 'carcass res' is 20K, but the final model ends up 96 polys? I really have no idea how to translate any of these parameter values into something meaningful. Is it just trial and error?

Anyway, I'll give it a try with manual retopology - but how did you actually get the fine detail into the map: does that just happen automatically when you merge the patch from from the retopo room? From there, if you want to take it to another 3D package do you export a normal map or use one of the depth map export options?

Thanks again.

b

[simmsimaging]

Here's my 2000 triangles shield that was made in no time (No retopology necessary):

Thanks for the help. I'm trying to figure out the steps involved in your process, but for now I'm stuck with 3DC hanging or crashing when trying to re-import my low poly mesh, or if that works then it hangs/crashes when trying the "merge to per-pixel with norma map" option. Frustrating.

b

[splodge]

Thanks for the help. I'm trying to figure out the steps involved in your process, but for now I'm stuck with 3DC hanging or crashing when trying to re-import my low poly mesh, or if that works then it hangs/crashes when trying the "merge to per-pixel with norma map" option. Frustrating.

b

That's odd, it shouldn't hang when importing a low poly mesh for Retopo. It always appears instantly for me. Are you sure you set the poly reduction size correctly? I'm wondering if you exported a high poly model by accident.

But yes, it always hangs around for ages when doing the "Merge for per pixel paint' stage. You've just gotta go make a nice cup of tea or something while you wait.

[simmsimaging]

That's odd, it shouldn't hang when importing a low poly mesh for Retopo. It always appears instantly for me. Are you sure you set the poly reduction size correctly? I'm wondering if you exported a high poly model by accident.

But yes, it always hangs around for ages when doing the "Merge for per pixel paint' stage. You've just gotta go make a nice cup of tea or something while you wait.

What counts as low poly? I exported it and reduced it to about 50K - which is low for this mesh. Still too high?

b

[splodge]

What counts as low poly? I exported it and reduced it to about 50K - which is low for this mesh. Still too high?

b

That's quite high. But I have done similar and I don't recall having any problems.

Perhaps you just need a reboot? Windows can get a little crazy if it starts to run low on ram.

[philnolan3d]

Thanks Phil. I was able to get a somewhat better mesh via 'quadrangulate and export' but I had to make a lot of tests and guesswork at the mesh values. In your example you have set the poly count to 6.85 million - how did you arrive at that number?

I'm still not sure what that number really means, and your 'carcass res' is 20K, but the final model ends up 96 polys? I really have no idea how to translate any of these parameter values into something meaningful. Is it just trial and error?

Anyway, I'll give it a try with manual retopology - but how did you actually get the fine detail into the map: does that just happen automatically when you merge the patch from from the retopo room? From there, if you want to take it to another 3D package do you export a normal map or use one of the depth map export options?

Thanks again.

b

My 6.84 million was just fairly random I think the default is around 4m and I just pushed it up a bit, didn't really care where it stopped. Honestly I still find that number a bit confusing myself, but if your carcass amount is the medium res, the millions represents what it would look like if it actually was that many millions.

Right, the low res for mine is what I'm starting with. Then you pick a medium "carcass" res ebcause you're going to be showing displacement, 96 polys is not much to displace, so it needs to be increased a bit. Then the rest is handled by the normal map and 3DC tells it to look like it's 6 million (or whatever) polys on that map.

This is probably easier to understand if you're importing a model from another program like LightWave, but it's pretty much the same deal.

As for how I got the detail into the normal map, yes it is just part of the merging process so it's automatic. As for exporting the normal map or depth map that's really up to you, depends on what you plan to do with them.

[splodge]

Simms, your resulting model looks strange and faceted. It shouldn't be that bad after quadrangulation.

I've just tested and verified that the baking is broken when baking for microverts (or Quadrangulate and Paint). The polygons are coming out faceted.

I'll go report it..

[simmsimaging]

I've just tested and verified that the baking is broken when baking for microverts (or Quadrangulate and Paint). The polygons are coming out faceted.

I'll go report it..

Thanks - figured it was just me.

In the end, and after a lot of experimenting and wasted time I have kinda given up on this workflow. I'm just using hi-res mesh output for now. This works fine with Vray at least (using Vray mesh and Vray proxy objects).

Thanks for the help in any case.

b

[WillBellJr]

Thanks - figured it was just me.

In the end, and after a lot of experimenting and wasted time I have kinda given up on this workflow. I'm just using hi-res mesh output for now. This works fine with Vray at least (using Vray mesh and Vray proxy objects).

Thanks for the help in any case.

b

Yes, if you're not concerned with optimized topology for animation or have to stick to a strict polygon budget for a game engine, save yourself the stress and just work with your medium to high-res models.

The only concern then would be memory resources for your final scenes.

-Will

[simmsimaging]

Yes, if you're not concerned with optimized topology for animation or have to stick to a strict polygon budget for a game engine, save yourself the stress and just work with your medium to high-res models.

The only concern then would be memory resources for your final scenes.

-Will

Yep, that's what I am doing, but there is another concern I've run into (and posted about in another thread) and that is: how to texture paint that hi-res mesh? The output mesh (either from Zbrush and decimation master, or exported as .obj from Voxel room with decimation) is too high poly to bring back in for texture painting. Obviously I don't need to sculpt it (no relief textures required) but painting diffuse/spec maps etc. becomes a problem. Still trying to figure out a way around that.

/b