Autotopology Question

[alvordr]

I'm working on making a pistol (no reference) and want to make it low-poly. I can do this by hand in Max, but I'm trying to do it from scratch in 3DC. What I have so far is the following. Everything autotopo's fine, except the item in the second picture here. I'm not sure how to tackle this, without manual topology. The autotopo looks horrid for this part, unless I make it way too high-poly. Am I being lazy?

[Tony Nemo]

It's hard to judge without seeing the topology.

[alvordr]

Good point. Here it is (and this is at 5000 polys for just that piece...way too high):

[AbnRanger]

I'll be honest with you....use Auto Retopo only when you are certain you don't need really clean geometry. It's great for secondary objects, like buttons, screws, belt's, bracelets, etc. Small elements that would be a tedious pain in the bum. But when we want clean looking geo...fuh' getta bout it (as New Yorkers would say). It's much quicker to use manual Retopo tools. Just use the Strokes tool to sketch the basic topology > Hit ENTER > use SPLIT RINGS to add loops where you need it.

I prefer to model things like this in 3DC because you don't have to piddle with verts and such. It's like modeling with Clay, and then the Retopo process is fairly easy cause, with the snapping to the high res object (Voxel model), it's like Paint by Numbers.

[Psmith]

That second part looks like it could use some AUTOPO guidance.

Try drawing some "through" guides (start drawing off the model) near the straight edges and longitudinally on either side of the exact center of each flat side. Then, draw some through guides perpendicular to the long edges - all along the length of the model.

The small details could use some spline guides around their perimeter. It's hard to tell from your picture whether the whole piece is a total solid, or not. It looks as if it could be made as a straight extrusion of a spline-based profile. That's the way I would construct it if I planned to use AUTOPO to make the topology.

While still in Voxels, use Res+ to scale up the model to half a million polys or so. AUTOPO seems to like hi-res voxel base meshes.

Also, try setting the "Additional smoothing" slider to 0 (in the opening AUTOPO dialog), just for comparison.

For a sculpt of this complexity, I would start with a Retopo resolution of at least 1200 polys.

Greg Smith

[alvordr]

I hear ya. So, I've managed to manually retopo this to just under 1000 polys for that one piece (ugh!). Still a bit high, but hey...I want the details, right? My next step is getting as much of the details in it as reasonable. This is what I like least about low-poly modeling, is that it looks horrid.

MergForDPDisp result:

[alvordr]

Greg,

Thanks to your tutorials, I was able to get this far with the sculpt and I love it! Thank you. I'll try increasing the resolution of the base voxel mesh. Meanwhile, I tried pulling in this manually retopologized mesh as a reference for the thing and came up with the images above. It's not bad, not great. My main concern is that I'm going to go way high on polys as I keep doing the different pieces. Even if I'm having to do most of it manually, this is still a HUGE time saver in my workflow. I'm super happy with 3D Coat.

[alvordr]

After Merge with NM (per-pixel)...Merg Patch (per-pixel) looks the same:

[alvordr]

So, I increased the resolution to 6 Mil + polys of the voxel mesh, then did the Autotopo, both with guides and without, both with smoothing at 0 and at 1. They seem to put me at around 2.4k polys and have weird streaks in the normal map, but over all it looks sharper than my previous one. Using my manually repoto'd mesh, it looks the same as above.

[Psmith]

It looks like the area with the grooves needs some straight line "through guides" (one on each edge and one in the middle of each groove). Just start drawing the guide off the mesh and end it where the groove stops.

The curved portion on the bottom needs more polys and more definition. Make sure the voxel sculpt is absolutely "clean" in this area - and try adding some density shading (using the spline tools) here and over the grooved area.

I believe it is possible to get a good AUTOPO mesh if you experiment a little more.

So much less laborious.

Of course, hard core poly modelers would simply suggest modeling everything, including the details, by hand.

Greg Smith

[alvordr]

Greg,

Yes, I thought the same, but the topology isn't working even with those guides. I believe I can do this, but for now I was able to get this down to 600 or so polys, but using ZBrush decimation, instead. It also triangulated it. This isn't a deal breaker, as the game engine would ultimately do the same. However, I always prefer quadified topology. Thanks for the tips. I'll keep at it.