haikalle

Improving the voxel in surface representation mode

22 posts in this topic

I started this new thread for this topic.

Let's talk about this video. http://www.vimeo.com/11555496

I think that there is some room for improve how the cursor moves on the surface. In the beginning

of the video you see how I slide the cursor over the edge. You can see that rotation of the yellow circle is calculated

according the area inside of it. Even when the center of the cursor is on flat surface it's rotating because yellow circle already

passed the edge. Then I move the cursor to other edge. The yellow cursor dosen't rotate. Why? Because it seems that surface tracking

is camera based. If the surface is hidden (behind the edge) it dosen't change the cursor rotation. For me it sounds better if this could

working diffrently. It should matter also what is behind the corner. Now 3d-coat dosen't do that. MAybe this is the reason why sometimes

spikes are created so easily.

EDIT: well, in my tests it seems that all spikes in surface representation always happens because of this, so fixing this

and we could have spikes free models.

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I did some more tests and it seems that there is 2 major problems why spikes occur.

1. The rotation of yellow circle depends of the angle of the camera. Here is two images. I'm placing the cursor exactly

in the same spot on the surface, but because the angle of the camera is diffrent also the angle of yellow cursor is diffrent.

If we could change this from camera based into surface based rotation, that would help a lot.

post-1165-12733154449842_thumb.pngpost-1165-1273315452716_thumb.png

2. This problem occurs when the angle of the cursor normal and the surface point normal is over 90 degrees. 3d-coat moves all

the points that are less than 90 degrees but leaves all the points over 90 degrees where they were. After that those points are

out of the system and the only way to save them is to go back to voxel mode and smooth them out.

post-1165-12733154572869_thumb.png

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I have some more problems though.

Question: after finishing with surface (voxel) mode do we have to turn to voxel mode before go for retopo etc?

I had a crisp enough sculpt and in the end I returned to voxel mode, had to smooth it, finished with a typical not crisp 3DC result.

For the moment do what you can in voxel mode (never surface mode) do some topo, increase resolution of the cage as much as you can (unfortunately not too much), export this quad mesh to zbrush, reconstruct sub levels and have a nice and creative day. Later you still can import the obj again and paint textures in coat (if you like). And still, I enjoy working with these two apps together. In a few months you'll be able to do it in blender too (instead of zb). (I already did it)

3DC offers some possible workflow that is not working (or has many bugs) for the moment.

I can't live without voxels and have to re topo and re sculpt again, thats OK.

I haven't seen any crisp sculpt in the 3DC gallery so far! If there are some, these involved zbrush too. Lets face it. After all zb has some reputation...

I maybe wrong but I'll say it again haikalle, avoid surface mode!

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You don't have to go back to voxel mode. You can stay in surface and merge from there. It takes longer time but it works.

I really like the voxel surface mode, because it's fast. Sure there is spikes and etc... but it's fast.

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Yes, I would return to voxel mode before going into the retopo room. Merging into the paint room is slower in surface mode from also from my experience too. I like surface mode for getting the major shape of the model from a appox. 200,000 to 1,000,0000( you could go higher depending upon what you are doing) and some low detail that will be enhanced using voxel brushes. I really like the combination of using surface mode and voxels,each has it's own strengths...

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I haven't seen any crisp sculpt in the 3DC gallery so far! If there are some, these involved zbrush too. Lets face it.

You are kidding right?

Juan Carlos take on Pixar's Mr.Invincible is super crisp and that is pure 3DC work.

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I guess crisp is a matter of opinion... I have yet to see some sculpt taht goes to detail like fine wrinkles and such. I don't like the idea to be forced to use normal map painting for that matter...

I guess I'm in a truthful mood tonight, cause i can't help but say what's been on my chest for too long now.

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I have yet to see some sculpt taht goes to detail like fine wrinkles and such.

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Touche! :)

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While you can go into super fine detail, this is how I did my old man sculpture in the early voxel days, really fine wrinkles and pores. I decided it wasn't necessary and found it easier in my big projects after that to stop using voxels before going into the really fine details. It's much nicer to do those in the painting room.

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When I say crisp sculpture I mean something completely different. Its about simple crisp precise forms. Precise! These above are just random effects. Precision is the heart of art. Some alpha projections, pores etc are not my concern. This is essential.

This is much crisper than these examples above

http://www.3d-coat.com/forum/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=6936

but all these are still rendered in voxel room. I didn't managed to export this 'crispness' to other apps though.

IMO if you believe in 'pores' go for a zbrush license. A base 'box' modeling and a surface zb sculpt is the best way. If you believe in real sculpture then you're in trouble. Thats why I bought 3DC the second day I tried it. Many bugs, lot of work, optimization is needed but its a more appropriate approach. Now I can export it in zb and do some fine details, some precise simple lines. You may not like what I said, but thats what I believe my friends. Please don't misunderstand me, not an offense.

I'm not interesting in VG, cinema and comics industry, that's for sure. Feidias, picasso, giacometti, deChirico, rodin, degas, ancient Egypt, Americas etc etc are my references. And the only tool I'm asking in this topic is a nice flattener :) .

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And did you ever ask Juan about lag time and having to wait for merging and quadrangulation/exporting an object like that? Just because you can do some decent painting in Microsoft Paint, if you had the patience and put in the extra effort, but we all know how that compares to doing the same thing in Photoshop or Corel Painter....touche deuce.

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Thanks for all for sharing some good info. Let's try to find a solutions how we can help to Andrew to fix this issues.

Saying "this is the problem" is good, but saying "this is the problem and this is the way

how we can fix it" is even better. Now when Andrew is taking some time to be with his family awhile(with

very good reason) we have time to think how 3d-coat works under the hood. And maybe find

something helpful for Andrew, when he comes back.

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We are at least 3 to understand the problem with 3dc, when i mean "fine wrinkle" i don't mean draginf the brush every two milimeters for the sake of it. I mean being able to define sharp and clean details in a reasonable amount of time not taht wobly/bloby uneaven surface representation that 3dc painfully output in most cases. There's indeed the paint room, but maybe, i don't know, painting a 3d detail with a 2d effect is not cutting it...

I don't know i like to be able to predict my actions, bumpmaps are a post work in texture mode, not a sculpt thing. All I get in 3dc is large smooth shapes, which is fine in early stages, but when i want to tighten my sculpts i simply can't with the performance issues.

All i, and i'm pretty sure i'm not the only one at all now, is a way to work progressively on the structure of the sculpt to define clearly my planes and build all the little nuances of a sculpt. Perf don't allow that.

And haikalle may be onto something here for starter.

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These above are just random effects.

Not at all.Its extrude brush with the sharp pen.So its pure sculpting my friend.

I posted the old man in relation to the other dude comment about the impossibility to do wrinkles and stuff.

I know you are not concerned with this.

When I say crisp sculpture I mean something completely different. Its about simple crisp precise forms. Precise!

This is much crisper than these examples above

http://www.3d-coat.com/forum/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=6936

Sorry,but no.

Juan's take on Pixar charcter is much crispier than your bust copy.The lines are more defined and sharper.

Your bust has absolutely no definition to the mouth (its not a critic,anyway..its a copy)

but the fact is that its far less "simple crisp precise forms" than that "silly" movie character.

Also when you say that "Precision is the heart of art" I would just like to point out that a lot of artists that you quote as references

would not agree with you at all,especially Giacometti.

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OK artman, we can't understand each other now, maybe in the future. As for giacometti, don't expect me to post the whole DVD here, try to find it, one of the best. Face him, lol he was a great man anyway. A philosopher also. Self biography of deChirico is great too. Movies about picasso, especially when showing how he paints in slow motion. So we like almost same artists but have different opinions, thats not bad at all.

I'm older than you thats all, have a look here http://www.cangelaris.com/art_zisi.htm :drinks:

Haikalle: you're right, I'm trying to show how I see 3DC, what kind of workflow we may expect, what's the 'nature' of this app, why all these weak points exist. Its easy to say I want a voxel modeler with a zbrush behavior, then convert this to quads, paint it etc etc. And most important, all these working smoothly. If this can be done, then 3DC will be the best app ever. For the moment I wish a simple combination of two or three tools, an optimization of topo and uvs rooms. Thats all for the moment.

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That is just a head. Try creating a full human figure at that detail level and you're going to suffer. It'll be 64 million polygons at least and 3D Coat would die. ZBrush can handle that kind of detail by temporarily dropping down to a lower subdivision level whenever necessary.

I agree with Michalis, high poly modeling isn't just about superficial details like skin pores, it's also about sharply defined edges on things like eyelids and the skin fold above the eye, or nicely defined finger nails.

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First I have to say that I'm sorry about yesterday, it dosen't happen again. okey, back to bussiness...

I did some more testing and let's take this picture to talk about it.

post-1165-12735541251858_thumb.png

Here is a surface and and the cursor. In current 3d-coat, the cursor would be flat because the angle of the camera

but here I fixed it into surface based tracking to show something else. When you add the surface. That's okey. You can't

create spikes when you add surface. It's because then it only works with points where the alpha is less than 90 degrees.

In this situation it is good.

But the problem is when you use CRTL, take a surface away. In the picture you can see that inside of radius there is points with

alpha more than 90 degrees. Again they don't move and that is bad in this situation. There is diffrent ways to make this better.

If you have used sculptris. It actually smooth unwanted spikes. That is the reason why the surface moves after a stroke. Maybe

someone of you know a good way how to handle these situations, so please give some feedback.

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Let's talk about this picture. post-1165-1274773475144_thumb.jpg

This is from voxel wire. You can see that the density is uneven all over the surface. Even the "very dense" area, there is many edges but they are going into

same point which is bad for detailing the surface. I see two options how we can make this better

1) Focus to Voxels: Improve the algorhytm how the voxel surface is build. The goal to have smooth density

all over the surface.

2) Focus to Voxel Surface: Right now if we press that small icon to go to surface mode. It leaves mesh density like it is in the picture.

We need "smooth all" button in surface mode. That would help to get smooth density and from there it would be better to start multi-resolution

surface sculpting in the future.

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One more picture. Here I tested brush stroke in diffrent modes. First is in voxel mode. Second is in voxel surface mode. It's getting better.

Last one is in voxel surface mode and manual smoothed area and then stroke. This gives the best results. So overall result from this test is that base mesh density have to be

smooth if we want to nice results.

post-1165-12747766327505_thumb.jpg

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The conclusion I've come to is that if you want to draw details with sharply defined edges then you must use a very high resolution voxel model.

The poly mesh generated by 3D Coat needs to be generated quickly and so it's not possible for it to be super efficient with an even density.

Maybe a solution could be to have a 'Recalucate Mesh' button that the user could hit now and then, but this would mean having to wait for a minute or two. And we've all seen how people hate waiting for 3D Coat to do stuff.. :)

Andrew has said that he plans on adding a regular multires/subdivision mode (like ZBrush or Mudbox). So before entering this mode it's likely that 3D Coat will recalcuate the mesh resulting in an even density, and possibly quads.

Having said all this, I wouldn't be surprised to hear that Andrew is reconsidering his approach and may decide to adopt Sculptris' method instead. Voxels are definitely the future, but right now most people don't have the computing power to handle them.

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This behaviour is still there. I think that we all love new multi-res mode but until this bug is fixed. We can't use it with

full power. This only happens when you remove (ctrl) surface. If the angle of brush normal and surface normal is over 90 degrees,

3d-coat dosen't handle it so well. And it takes quite alot time to remove to spikes. Anyway 3.5 rocks :D

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