How to (auto)retopo hard surfaces

[Adivaki]

Hi,

Could someone tell if there's an effective way to retopo hard surface please ?

I'd like to make starship in voxel mode and after retopo and export it to another 3D soft.

We've seen the great demo about rich primitives on 3DC's main page :

So, I was so impressed that I bought some tutorials from Javis Jones to know how making a starship in voxel sculpting :

3D-Coat Video Training:Voxel Sculpting|Hard Surface Compendium

http://javisjones.com/products-services/videotraining/

The tutorial is great. But at the end, once the starship built, we try to retopo and realise that it's doesn't really work with hard surfaces because the result is a bit messy !

So, does it mean that voxel sculpting and retopo in 3DC are essentially made for organics shapes ?

So if I make a starship in voxel sculpting in 3DC that's great. But I can not use it outside voxel room ?

thank

[Psmith]

Adivaki:

It is very difficult to turn a hard surfaced, voxel sculpt into an accurate polygonal mesh which respects all hard edges. Javis' method shown in his video is the best I've seen.

At this point in time, I'd recommend using another program for hard surface modeling - importing the model into 3D-Coat only for texturing or manipulating topology.

One app, which is reasonably priced and has great automatic meshing tools for hard surfaced models is Groboto. All models are created by means of a wide variety of primitives and shapes produced with boolean interactions of these shapes.

Groboto 3 Modeling Methods

Greg Smith

[philnolan3d]

For some things on a hard surface model like the gas mask I recently did (in the WIPs area) I did a part in LightWave, then brought it over to 3DC to add stuff and edit it since it's easier to do without worrying about topology. However I would retopo manually, not use auto-retopo.

[digman]

Manual retopo with some good advance planning is the key for this type of work.

layers used effectively.

good symmetry.

instances,you can retopo one voxel object then use that mesh as base for all your identical instance voxel meshes using the import mesh feature in the retopo room.

You will be using the move vertices and edge tool to help keep your polygon lines straight around the hard edges.

Switching to Orthographic mode when retopoing for hard surfaces is not a bad idea.

Is it fast? no... but possible, yes...

I would suggest make a simple test hard surface model and then manual retopo it and get a feel for what you can do. That is my usual way for testing out what I can do in 3DCoat.

[Adivaki]

Thanks all for the help.

As you said Digman : "Is it fast? no... but possible, yes...".

That I wanted to know.

I'll give it a try.

[philnolan3d]

Agreed that it's not as fast, but it's still a lot faster than modeling by hand.

[michalis]

instances,you can retopo one voxel object then use that mesh as base for all your identical instance voxel meshes using the import mesh feature in the retopo room.

I missed something here? How?

[digman]

Test this out just with a voxel sphere to get the idea of the workflow

Create one voxel sphere

Make one instance of that sphere, It will make the instance sphere a child of that sphere. change the parent of the instance sphere to "Root" under the vox tree tab

Move the instance sphere off to one side or the other anywhere in 3d space

Hide the instance sphere

Auto retopo the voxel sphere at 200 polygons just for the test.

Create a uv map for it.

Export that retopo sphere mesh from the retopo room under the retopo menu

Hide the retopo layer. not necessary but helps keep things nice and orderly

Now back in the voxel room hide the voxel sphere. not necessary but same as above

Go back to the retopo room. Now only the instance sphere is showing.

select the Uv set box and in the drop box list select "add new uv set". Name it. This uv set will recieve the uv map from the exported sphere mesh.

Make sure you have selected the uv set you just created in the Uv set box.

Import the sphere obj mesh you just exported.

Use the transform tool to position it over the instance sphere in 3d space, press enter and snap to the instance sphere if you want to.

The mesh will snap to the instance sphere and the uv map will be placed in the uv set you created for it.

Done.

This might seem alot to do but really it is fast...

You just created one mesh with a uv map that you can use for all your identical voxel instances...

I really need to do a combination video tutorial of this method and the one I described in this post.

http://www.3d-coat.com/forum/index.php?showtopic=7263

[digman]

Here is a picture of the voxel object and it's instance in the paint room each with it's own uv map and as separate objects...

Only one uv map is showing in the texture editor but the other is in the drop down list.

[Bob Morane]

Hello everyone. I've started playing a bit with the Demo of 3DCoat a few days ago. Had my eyes on the soft for several months thought. I would really like to know how to retopo Hard Surfaces too. I already figured auto retopo is a no-no for hard surfaces but even manual retopo doesn't seem to work very well, or more probably i'm really bad at retopo.

Manual retopo with some good advance planning is the key for this type of work.

layers used effectively.

good symmetry.

What kind of advance planning and how does layers help me for this?

I thought hard surfaces would be quite easy to retopo with few polys but actually they are extremely tricky. It seems no matter what i do i can't set a point on an edge. It will always fall on one side or the other.

For some things on a hard surface model like the gas mask I recently did (in the WIPs area) I did a part in LightWave, then brought it over to 3DC to add stuff and edit it since it's easier to do without worrying about topology. However I would retopo manually, not use auto-retopo.

I mostly tried adding details to (very basic) objects created in an external modeler. Is it possible to use the original mesh as a guide for retopo when doing this?

Goboto is nice but unfortunately doesn't import external meshes.

[Javis]

Hi Adivaki. Thanks for picking up the video!

Autopo (regarding hard surface objects) can get a nice close approximation, but if you need a specific mesh... It's just not going to do it for you. The painstaking work of manual retopology or modeling is the only way to go. Now that's not to say simple hard surface objects wont work, generally they do. But the more complex your object becomes the less it will be viable for autopo.

Also, if you plan on creating background/static objects, autopo is fine, even for hard surfaces. So long as you don't mind rendering (or in a game engine) the object with a normal map. End users will never tell the difference.

[Bob Morane]

Ah, i managed to get somemething that slowly looks like the beginning of a result by manualy drawing quads. However, i miss the ability to constrain drawing in one direction, i tried all modifier keys (like ctrl, alt ...) while dragging my quads, it seems like i can't force them to be drawn in one axis.

Javis, your videos would probably be my first purshase after 3Dcoat but i first want to be sure i can get something out of it. I don't want to by the tutorials if i end up not buying the software

[AbnRanger]

Ah, i managed to get somemething that slowly looks like the beginning of a result by manualy drawing quads. However, i miss the ability to constrain drawing in one direction, i tried all modifier keys (like ctrl, alt ...) while dragging my quads, it seems like i can't force them to be drawn in one axis.

Javis, your videos would probably be my first purshase after 3Dcoat but i first want to be sure i can get something out of it. I don't want to by the tutorials if i end up not buying the software

These are some training DVD's that I would recommend as well:

http://www.kurvstudios.com/3D-coat/voxel_sculpting.php

[philnolan3d]

These are some training DVD's that I would recommend as well:

http://www.kurvstudios.com/3D-coat/voxel_sculpting.php

FYI Kurv no longer sells those, they are just still on the site. Leigh has some training on his own site though:

http://scary-monsters.org/index.php/workshop

[Bob Morane]

Bah, what looked like a good start ended up like a disaster

OK, here is a view of the door panel.

As you can see it was a very simple (and boring) mesh and i wanted to give it some details. I know it's possible to model this directly in a usual polygon based modeler but i wanted to try 3DCoat on this and see if it was easier. Indeed doing this was pretty easy with voxels and the help of the tinker objects, but than comes the hard par (for me), re-topology.

What do you think of it? Is it possible to re-topo this or not? If possible how would you start? I'm totally new to 3DCoat and all the tutorials here are based on organic objects or simple primitives. I'd like to be able to tell exactly what i can do, and what i can't do after the end of the 30 days trial.

[philnolan3d]

Sure something like that would be very easy to retopo, probably best to do it manually. Here's really quick example:

http://screencast.com/t/NO7x0X4GQ2s0

[Javis]

Ah, i managed to get somemething that slowly looks like the beginning of a result by manualy drawing quads. However, i miss the ability to constrain drawing in one direction, i tried all modifier keys (like ctrl, alt ...) while dragging my quads, it seems like i can't force them to be drawn in one axis.

Javis, your videos would probably be my first purshase after 3Dcoat but i first want to be sure i can get something out of it. I don't want to by the tutorials if i end up not buying the software

Yeah I hear that. Though I've had a few instances where I bought training first to see if I wanted to even buy the application. It's saved me a couple thousand dollars actually, lol!

A note on a certain 3rd party training vendor...

Definitely get materials directly from the artists or Liberty3D for now. Buying from that particular 3rd party vendor is, well, not going to end well for anyone but one person... And I can tell you that person wont be you or the artist of the training materials.

[Javis]

Bah, what looked like a good start ended up like a disaster

OK, here is a view of the door panel.

As you can see it was a very simple (and boring) mesh and i wanted to give it some details. I know it's possible to model this directly in a usual polygon based modeler but i wanted to try 3DCoat on this and see if it was easier. Indeed doing this was pretty easy with voxels and the help of the tinker objects, but than comes the hard par (for me), re-topology.

What do you think of it? Is it possible to re-topo this or not? If possible how would you start? I'm totally new to 3DCoat and all the tutorials here are based on organic objects or simple primitives. I'd like to be able to tell exactly what i can do, and what i can't do after the end of the 30 days trial.

Phil's video is a great example on how to do it. Definitely. I've got a new retopo series coming out very soon that covers similar vox sculpts. Semi-organic with some hard surface objects.

Another approach to retopologizing that object would be to cover up those insets with larger polys, the details will be baked to texture maps.

That all said, while I think 3D-Coat is an amazing application, it is still better suited, at least in the auto retopology department, for organics or not too complex hard surface objects. Manual retopology can take, in some cases, just as much time to model as to retopo. So it's a case by case basis. Personally though. I never, ever, rely on a single tool too much. I was using 3DC with LW a lot, but now I use 3DC with Modo for certain retopo functions.

[Javis]

Here's a quick example with what I would probably do. (See attached image)

[Javis]

Here's another example, if you don't need all quads and don't wish to have poly edges covering those paneling. (Note there are n-gons)

[philnolan3d]

Yes I would probably do the same as your first (quad) example, in most cases.

[AbnRanger]

Yeah, use normal maps to show details and save yourself some time...on the modeling/retopo and rendering side. However, just be aware of the limitations of Normal Maps. In this case, if the inset shapes were extruded upward and not inward, then you may have to do the extra work to build it with poly's, cause at certain camera angles you'll notice that it's just a trick and there is no substance/geometry there. But since it is inside the object, you can likely pull it off with just normal maps. It depends on the complexity of the shapes, obviously.

[Bob Morane]

Thanks everyone.

That video is actually close to what i tried when i first posted i got a beginning. Not sure when i messed the thing up. I tried filling gaps with the points/faces tool rather than the cap tool. Maybe it's what caused some issue or maybe i accidentally dragged some edges or vertices, i noticed it can happen with some tools if i click in faces when trying to rotate the view. Actually i was working high zoom in and when i zoomed out to see the full result after doing the upper part all the bottom part was messed up.

OK, i'll try again this way. Looks easier than what i was trying currently.

RE : Normal map.

Ah, thanks for the info about recessed vs raised areas. I thought normal maps were better suited for finer details because when i tried on large features it was evident i used an optical trick. Was raised features.

However, i'll still retopo it cause 1) i want to know if i can do it and 2) i'm still unsure where i might end up using/re-using it and i might want to have actual geometry at some point.

I'll do the normal map too and try and see for myself how close i must render to notice any difference.