zbrush to 3d coat for retopo help please

[iangregory]

Hello everyone,

I recently watched the excellent video "Advanced Retopology" by Leigh Bamforth and hoped someone could answer some basic questions for me.

I noticed that the 3d model Mr. Bamforth used in his video was modeled in Zbrush. He uses 3d coat for the retopology and unwrapping.

Could someone provide me with basic steps to import my zbrush model into 3d coat so I can try to retopo it? Is there a recommended "Use less than x number of polygons" when you export from zbrush? How about any maps you created in zbrush? Should they come in too?

Your help is appreciated. I have searched the forum for import zbrush mesh for retopology but didn't find anything. In the video, his model is already loaded into zbrush when the video starts.

Thank you in advance,

Ian

[philnolan3d]

I don't know anything about the recommended poly count, but try using File > Import > Reference Mesh. This will allow you to import fairly large objects in the LWO, OBJ, FBX, STL, or PLY formats, then switch to the Retopo tab. The Reference Mesh is just for building retopology on so any UV maps or materials won't matter.

If your object is too large for the Reference Mesh option you can try importing it as voxels where the poly count doesn't really matter. As an experiment a while back I did this with the Stanford U. "Lucy" model, which is notorious for it's high poly count and as you can see here it worked great:

[iangregory]

Thank you Phil. I enjoyed the video you posted and will try your suggestions.

Ian

[philnolan3d]

No prob, I don't use ZB (I have 3DC ) but it should work out. Good luck.

[geo_n]

Leigh Bamforth is in these forums. Maybe he could explain his workflow further.

Btw, is that vid a webinar or really made for tutorial video?

[iangregory]

Leigh Bamforth is in these forums. Maybe he could explain his workflow further.

Btw, is that vid a webinar or really made for tutorial video?

If Leigh sees this and responds that would be nice. Phil's advice did work. I wasn't able to merge the model Phil shows on his video as a voxel but was able to bring in a high poly model from zbrush as a reference mesh. I think that was more likely my inexperience (probably did something wrong) than 3d coat.

I believe the video was a webinar, but honestly the quality and instruction is great. I've bought some webinars that were pretty disappointing, but this one was really well done with a large clear screen recording.

Ian

[James Thornton]

You have to remember that to project the hi res details in ZBrush, all you need is a new base mesh that is representative of the main form in shape and scale.

In other words, when creating this new base mesh in 3d Coat or ZBrush, you don't have to retopo over a 20 million poly sculpt. You can lower the resolution of the polys as long as it still holds the form. Not having skin pores and infinitely small detail in your reference mesh won't matter.

That will allow you to leverage 3d Coat's awesome retopo tools if the mesh is too heavy for the normal import as a reference. It will also make everything more responsive.

Once you have this new base mesh obj, you can open it in ZBrush and project the hi res details from the heavy mesh. Viola!

[philnolan3d]

But why go back to ZB at all when you can make the normal map right in 3DC?

[iangregory]

Good suggestion James! Thanks.

[James Thornton]

But why go back to ZB at all when you can make the normal map right in 3DC?

Because retopologizing over a dense ZBrush sculpt in 3d Coat is ....s....l.....o.....w....

Even just a 3 mil mesh is sluggish. I've got some that are in the 20's that you can't even open.

Meanwhile, even a mesh that's 250k is so smooth to retopo it could make you grin ear to ear. I can get away with something around 50k.

My suggestion is if the ZBrush sculpt Ian is trying retopo is fairly dense, which is likely. So a great way to leverage the awesome tools of 3d Coat without slowing down the system is to export a lighter mesh that still holds the form. Exporting an obj from a middle ground subdivision level still retains plenty of shape to create the new base mesh.

In this situation, projecting the details and generating the displacement/normal map in ZBrush makes the most sense. It's the path of least resistance. As is doing the retopo in 3d Coat.

At the time, ZBrush retopo calls for tediously clicking each vert individually. So this is a great way to leverage each app when using them together.

[James Thornton]

Good suggestion James! Thanks.

No problem, and good luck!

Here's another tip if you like using these apps together, but want to start off with voxels. Do your sculpt, starting at a lower res and gradually increasing. Jump into the retopo room. Use the tools to do a very basic, low res retopo w/ good edge flow. Initially, it won't retain the detail of the voxel sculpt due to low resolution. Export this base mesh.

After you've done the low res retopo, you can subdivide it. The mesh will vacuum to the voxels (genius!). Use the brush tool, sometimes with shift to smooth to clean things up between each time you subdivide. Keep dividing until you have a mesh that represents the voxel sculpt. Export this as a hi res mesh.

Import the base mesh and hi res mesh into the ZBrush tool palette. Append the hi res to the base mesh as a subtool. Under tool>subtool hit ProjectAll. This will project the hi res onto the base mesh with subdivisions! Now you can delete the hi res subtool.

This, of course, is if you want to do detail in ZBrush. You can further detail the new mesh in 3d Coat as well, by sculpting the mesh, and through painting (sculpting) difference maps, even vector displacement!

Just thought I'd share because I'm having a lot of fun with it ; )

[Mix Mash]

I suggest that if you want to retopologise in 3d coat only then there's a plugin for Zbrush 3 called "Decimation Master" that takes your high res mesh and reduces the number of polygons of the mesh while keeping the major form intact. There is a video tutorial for the plugin as well somewhere (it might be in the Zbrush classroom page). Since the mesh is so much smaller when you are done, your reference mesh will be easier to work on when retopologising. But Make sure that you DON'T save your Ztool after you use decimation master because you will be saving over the original mesh that probably has all the subdivision levels, textures, etc... The thing is that Decimation Master works so well that sometimes you can't tell the difference between your original high res mesh and your decimated mesh until you zoom in.

I hope this helps you in some way.

Cheers,

Paul

[Taros]

Because retopologizing over a dense ZBrush sculpt in 3d Coat is ....s....l.....o.....w....

Even just a 3 mil mesh is sluggish. I've got some that are in the 20's that you can't even open.

Meanwhile, even a mesh that's 250k is so smooth to retopo it could make you grin ear to ear. I can get away with something around 50k.

My suggestion is if the ZBrush sculpt Ian is trying retopo is fairly dense, which is likely. So a great way to leverage the awesome tools of 3d Coat without slowing down the system is to export a lighter mesh that still holds the form. Exporting an obj from a middle ground subdivision level still retains plenty of shape to create the new base mesh.

In this situation, projecting the details and generating the displacement/normal map in ZBrush makes the most sense. It's the path of least resistance. As is doing the retopo in 3d Coat.

At the time, ZBrush retopo calls for tediously clicking each vert individually. So this is a great way to leverage each app when using them together.

Retopo a 3 Million Object in 3DCoat can be very fast, if you know how... I already retopologized 7 Million Poly Objects and more. Ok, that's not 20 Millions, but the reason here is my memory limit of 3 Gbytes (for now...).

Just import the Object into the voxel area and NOT! into the paint area or as a retopo reference. After converted to voxels, the imported object can be easily and very fast retopologized in 3D Coat. I've made very good experience. You have to give a good voxel resolution to have good details. You can do this while the import. Just set the scale factor to a value of 3 or 4, or more. Maybe you have to test some values to reach a nice result. But you don't need a full detailed object in 3DC to retopo it, just the main shape should be enough. After the retopo I would bake the normals in zBrush, because there you have your main template and the full details.

If you don't know how to merge a OBJ model into the voxel area, just ask.

Be creative

Chris

Small expample:

[cuffins]

@James Thornton

very good explanation of the workflow!

@Taros

sure importing into voxel room is a possible way, but if you ever tried to import an object into voxel room that has some holes (like eyesockets) in, you will see that's not practicable. I'm always getting artifacts in such regions...

[philnolan3d]

sure importing into voxel room is a possible way, but if you ever tried to import an object into voxel room that has some holes (like eyesockets) in, you will see that's not practicable. I'm always getting artifacts in such regions...

You know there's a new function, Make Mesh Closed, that fixes that?

BTW the Lucy model in my video that I posted above started as about 28 million triangles. The voxels shown in the video is about 7.4 million and moves just as easily as a 6 poly cube (recording the video made it appear a little sluggish, but it's not). You could increase it further and might get slightly sharper quality, but I don't think it's really needed.

[cuffins]

You know there's a new function, Make Mesh Closed, that fixes that?

BTW the Lucy model in my video that I posted above started as about 28 million triangles. The voxels shown in the video is about 7.4 million and moves just as easily as a 6 poly cube (recording the video made it appear a little sluggish, but it's not). You could increase it further and might get slightly sharper quality, but I don't think it's really needed.

No I don't know that Make Mesh Closed will fix that...have to try it! THX for the tip!

[philnolan3d]

No prob, I didn't even notice that button until someone else mentioned it in another thread. I tried it myself and it worked wonderfully.

[cuffins]

No prob, I didn't even notice that button until someone else mentioned it in another thread. I tried it myself and it worked wonderfully.

I know this button, but it would never had occured to me doing the job...

[iangregory]

Thanks to everyone for all the great advice! I'll have time this week to try out the different techniques.

Ian

[James Thornton]

Retopo a 3 Million Object in 3DCoat can be very fast, if you know how... I already retopologized 7 Million Poly Objects and more. Ok, that's not 20 Millions, but the reason here is my memory limit of 3 Gbytes (for now...).

Just import the Object into the voxel area and NOT! into the paint area or as a retopo reference. After converted to voxels, the imported object can be easily and very fast retopologized in 3D Coat. I've made very good experience. You have to give a good voxel resolution to have good details. You can do this while the import. Just set the scale factor to a value of 3 or 4, or more. Maybe you have to test some values to reach a nice result. But you don't need a full detailed object in 3DC to retopo it, just the main shape should be enough. After the retopo I would bake the normals in zBrush, because there you have your main template and the full details.

If you don't know how to merge a OBJ model into the voxel area, just ask.

Be creative

Chris

Small expample:

Hey, thanks for the tip! I learn more about this cool app every day. I suspect that getting good at converting poly meshes into voxels can come in handy for MUCH more than retopology. That's something I haven't tried.

It's good to know even though I'm having a lot of success with polys. Transferring to voxels for retopo is something I will definitely experiment with. Sounds groovy. Might add a step, but might add some advantages as well. Definitely worth a look though.

Cheers,

James

[philnolan3d]

I suspect that getting good at converting poly meshes into voxels can come in handy for MUCH more than retopology. That's something I haven't tried.

It's not too hard really when you use the merge tool and pick your object, before you hit Enter you can see the estimated poly count in the Params panel. Scale up the proxy object but keep it low and hit Enter, if that's not enough detail hit Undo and scale it up a little more then hit Enter, repeat this until you have the detail you want.

[James Thornton]

Thanks for the tips! Should have a chance to get back at it during Thanksgiving break. I want to fully study this software if time allows, so I appreciate the advice.

[SYN7AX3RR0R]

Scale up the proxy object but keep it low and hit Enter, if that's not enough detail hit Undo and scale it up a little more then hit Enter, repeat this until you have the detail you want.

instead of scaling the proxy you can also do this:

VoxTree (pop-up) > Select Layer > Increase Resolution of Current Object (button on the bottom)

you will get a multiplier number to indicate rez

[LJB]

Hello everyone,

I recently watched the excellent video "Advanced Retopology" by Leigh Bamforth and hoped someone could answer some basic questions for me.

I noticed that the 3d model Mr. Bamforth used in his video was modeled in Zbrush. He uses 3d coat for the retopology and unwrapping.

Could someone provide me with basic steps to import my zbrush model into 3d coat so I can try to retopo it? Is there a recommended "Use less than x number of polygons" when you export from zbrush? How about any maps you created in zbrush? Should they come in too?

Your help is appreciated. I have searched the forum for import zbrush mesh for retopology but didn't find anything. In the video, his model is already loaded into zbrush when the video starts.

Thank you in advance,

Ian

Oh Man Sorry I did not see this. I have an intergration Seminar coming up toward the end of the month. I will cover how to take Highres .OBJ form another Dispalcement painting application and set up retopology fully in this class. But I have a small video on my Vimeo Channel. Theres a link in the Tutorials section.