Jump to content
3DCoat Forums

Vector displacement..?


herve_bis
 Share

Recommended Posts

  • Advanced Member

hello..

I have a question... how do you use the Vector Disp export from an object done in voxel room... ? big mystery .. :unsure:

let's say I have this model in voxel room, then in retopo room, I imported a flat mesh (with uv) and when 3D coat asked if I want to snap it, I said no.. now.. if I do an export vector displacement, I get nothing... where should I go from here..?

Thank you

h/

post-2277-0-69324600-1317139812_thumb.jp

Link to comment
Share on other sites

  • Reputable Contributor

hello..

I have a question... how do you use the Vector Disp export from an object done in voxel room... ? big mystery .. :unsure:

let's say I have this model in voxel room, then in retopo room, I imported a flat mesh (with uv) and when 3D coat asked if I want to snap it, I said no.. now.. if I do an export vector displacement, I get nothing... where should I go from here..?

Thank you

h/

If the mesh is beneath the object you want to bake details/shape from, it won't work. I presume the normals on the mesh point toward (not behind) the voxel object/reference mesh. That's why you need to conform your mesh (and snap it) to the shape as best you can. Try to run AUTOPO (automatic topology generation tool), and test the result.

One other note...not all render engines support vector displacement yet. Make sure to check that yours does before baking it out.

Link to comment
Share on other sites

  • Reputable Contributor

Herve, forgive me if this sounds like a stupid question, but did you create a UV map in the Retopo Room for it? That would be one reason why you don't get anything. With a UV map applied and merged to Microvertex mode, you can examine your VD map in the 2D Texture Editor. If it looks right there, then the only reason why you wouldn't get anything at render time is lack of support for it from your render engine. I think Mental Ray for Max only got support for it with 2012, and finalRender R3.5 for Max still doesn't have proper support for it yet. It has had a VD map option for a long time, but it doesn't work currently...so it could be on the render end, maybe?

Link to comment
Share on other sites

  • Advanced Member

Hello.. thanks a lot ABNRanger.. :)

well the app I am testing supports VD.. no problem... (cannot say more - NDA)

but what I am getting is a full grey map from 3DCoat... and the thing is.. IF you send it to the paint room (microvertex) we have no option to tell 3Dcoat to bake a VD instead of a simple disp map... that's the point..

the thing is.. I want to have a flat plane with the entire snake baked into a VD...

SO... if I try export VD from the retopo room... I get a full grey map. and IF I send it to the paint room.. the flat plane is automatically snapped to the snake form and a disp map baked for the details.. but this is not what I want...

btw, my plane that I imported is UV'ed

I am going to try importing a non subdivided flat plane (only one square polygon) and I will see what I can do..

But I still think exporting a VD map from the retopo room should work..

h/

Link to comment
Share on other sites

  • Advanced Member

I didn't know that 3DC had the ability to export Vector Displacement Maps.

It's my understanding that to extract VD the high res and low res meshes need to be connected in a subdivision hierarchy..at least that's how it works in Mudbox.. So how do you achieve that with a Voxel model. It's natural that you retopologize the Voxel mesh and bake your maps, but that won't work for VDM. Maybe there's some info in the docs, maybe you need to send it to the 3DC Sculpt room before you extract VDM.

Link to comment
Share on other sites

  • Advanced Member

hello... well I looked about everywhere, but there is info that I can find other then it imports and exports Vector disp...

the only way I can make it work at the moment (for exporting ) is to load a mesh in micovertex paint, then swith to sculpt, do whatever, go back to paint and then export the vector disp map...

BUT as far as I can see , the real benefit would be to be able to bake the voxel to it...

h/

I'd be VERY happy if Andrew could elaborate a little about this... :clapping:

Link to comment
Share on other sites

  • Member

Hi Herve_bis,

So the problem here is that you're wanting something not possible in your described workflow.

With current VD tech, you simply can't take two arbitrary meshes and turn one into another.

As mentioned by Ghib, VD does most definitely require a subdivision workflow(such as mudbox or Zbrush).

This is because VDM do not bake from a delta like a normal displacement map, but use the displacement tesselation

at render time to determine the final location of the subdivided polygon.

It does it this way because when you subdivide a mesh for sculpting, the Uv's are subdivided as well. So the

new position of the sculpted polygon can be represented as an RGB value showing it's offset to it's original

position.

To have a VDM work the way you'd like, would require a lot more calculation with a lot more room for various errors.

The Bake would have to take into account edge connectivity, somehow determine what parts of the source and target mesh

were "meant" to be representing the same part of the object(so you'd be talking about some sort of difference threshold

just for an initial pass) and then you'd have to have something in place for when crazy artists want to put a hole in the

sculpt when there are none on the low poly model(one of 3dcoats main benefits is the ability to put holes when and where you'd

like).

If it's the sculpting tools in 3ds you prefer and that's why you're not using Mudbox, a method that might work is to subdivide your

low poly mesh in the topo room over your sculpt(with snapping)a bunch of times(until you get the detail you want), export the

new hires retop as an obj. Import the original model as a base layer in Mudbox, subdivide up to the same level you were in in

3dcoat and import the highpoly retop obj as a new layer.... a hassle but it might work.

Hope this clarifies a few things for you.

Oh, I think the VDM in 3dc is just for when working on microvertex painting.

Good luck!

Link to comment
Share on other sites

  • Advanced Member

hello Heath_3D, thanks for your input.. :)

well, yes I do know that VD works only with microvertex.. but I was just hoping that Voxels could be baked to it.. but well not the case...

I have had success loading a plane in Microvertex, then in the sculpt room, I deformed that plane, then I went back to the paint room, and I could indeed output a VD map... so at least I do get something..

...

to be continued... :brush:

h/

Link to comment
Share on other sites

  • 3 weeks later...
  • Advanced Member

ok, now that I can talk, you should know that Maxwell 2.6 has vector disp as a new feature...

BUT, so far, the best bang is Mudbox... sorry to say Andrew..

If one wants a vector disp from 3D coat, the only way is to sculpt (lol) a base object in the sculpt room.. :(

Link to comment
Share on other sites

  • Advanced Member

ok, now that I can talk, you should know that Maxwell 2.6 has vector disp as a new feature...

I am currently testing but unfortunately don't get anything useful done.

It seems to render very fast but I fail to get things under control - whatever Map-Type and Parameter I try.

See attached - the first is 3DC, the second is Maxwell.

Generally - as you say already - having to use the Sculpt Room turns out as the largest limitation.

Hopefully in V4 (where Andrew said that one can Paint directly on Voxels) one can just run an automatic Retopo

after having finished the Painting and then save out Ptex Vector-Displacement.

If anyone else wants to try as well, the .3b-file is here.

post-575-0-95187300-1320512825_thumb.jpg

post-575-0-26694900-1320512852_thumb.jpg

Link to comment
Share on other sites

  • Advanced Member

Andrew, if you read this..

well that's the way I imagine it should work..

Imagine working with voxels... I would retopo a much simpler mesh, make UVs (or use Ptex), then move it to the paint room, where I would output a nice Vector Map...

h/

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...