Digital Art Zone

The decimate function in Hexagon is pretty handy if you’re a sculpture based modeller but one of the problems I find with it is sometimes it gets rid of edges I want to keep for seams for UV Mapping.

Is there a way you can select edges and tell decimate that these edges must be preserved during the decimation process?

I noticed too that symmetry isn’t maintained during a decimation so I’ve just halved the model decimated and then cloned the two halves back together. Is this the only way around that or is there another way to maintain model symmetry during decimation?

The decimate function in Hex is a horror!

Try using the free Meshlab http://meshlab.sourceforge.net/  it is really good for decimating and a thousand other mesh fixing functions.

It does triangulate everything when it decimates, which shouldn’t be a problem, but if you have to have quads, Blender has a very simple tri to quad converter - although it does leave some tri’s which can be manually converted in Hex.

Thanks! I’ll give that a go.

Wow…. MeshLab is one complex piece of software. What is the decimation function called in it?

Never mind, found it.

It does do a better job than Hex for sure.

Yes, it certainly is - I have no idea what 95% of it’s functions do - like all these opensource apps, it is pretty geeky and has virtually no instructions.

I’ve learned a bit simply by playing around.

Just for interest - you mentioned keeping seam edges - what app did you do the sculpting in that gave you any sort of edge loops?

I was just using the sculpting functions in Hex. I basically create a simple mesh with cubes spheres and cylinders stitched together then use the sculpting tools to build definition. That way I can keep the seams for UV mapping ease.

I see…

Did you know that if you UV map the original shape, you can apply smoothing and sculpt - as long as you don’t add or delete verts - and the map will still be valid?

You could even, if you keep DG active, export a bump map of the sculpted version, take the smoothing down, close DG, export as .obj and use the bump map for detail on the low poly version.  The bump map isn’t the world’s greatest, but you can improve the contrast in a 2d editor and it becomes reasonably useful - even as a displacement map, or converted to a normal map.

I like to make my mesh as high a resolution as I can get away with so that I have more to work with when I sculpt it and then reduce the resolution of the mesh until just before it starts to lose too much detail,

OK - same principles apply.  I’d like to see an example -Hex’s sculpting tools are pretty primitive, but I have seen a really good piece of work done with it.

Have you tried making a base shape in Hex and sculpting it in Sculptris (free) - a sort of a Zbrush lite?  It does automatic UV mapping, although it can then only be 3D painted.  That is what I mainly use Meshlab to reduce the poly count.