Talk:3dm2sculpt

3dm2Sculpt

I've been working on 3dm2scultpt, playing with the source. I've been reworking it's internals and at this point you wouldn't recognize it. I've fixed a few bugs in it and made it so it will output multiple surfaces per object. With multi-surface objects it scales all the surfaces as if they were connected. This allows for the user to be able to manually stitch the images together assuming the UVs are uniform along the edges. I'm thinking about adding automated stitching along with configurable UV resampling. It's going to take me a while to work this one out best. -- Strife Onizuka 03:05, 24 June 2007 (PDT)

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Ok...seems there's work left to be done. Made some stuff in Rhino for testing.

A bent cube - the "I can't possibly screw this up" example

• Sculpt Map | Screenshot in Rhino | Screenshot in SL

Teapot - a more complicated shape, the classic object for any 3d test

• Sculpt Map | Screenshot in Rhino | Screenshot in SL (the one on the right) (The one on the left is a torus, but it's lost its hole and split in half.)

Good luck though. Elle Pollack 20:06, 7 May 2007 (PDT)

Oh, thanks for the Bug Report. Seems like i should get a Demo of Rhino, too, to do more testing. So far, my Converter can only handle a single Object (i will change that, but each Object will result in another Sculptmap). Another Limit : the Object needs perfect UV Coordinates.--Cindy Crabgrass 21:13, 7 May 2007 (PDT)

I think the UV mapping could be throwing me off. What the heck is meant by "perfect" UV Coordinages? The above models all have a spherical map applied to them, which is what I had started to think was what was needed based on how the sculpt prim is based off a sphere. Then again, I've seen a lot of stuff in the last coupple days that seems to break that rule, like the heightmaps people have been doing in paint programs. I may have to pester Qarl some more. Elle Pollack 22:09, 7 May 2007 (PDT)

I did some more testing with Rhino Files and found something : most Rhino Objects are made of more than one Surface. The twisted Cube (i made one for testing) should have 6. My Previewer showed exactly one nice and twisted surface. Thats a Problem... can I create a Sculptie from multiple Surfaces ? More Research needed  :)

Let me quote Michael Gibson : I should mention that this algorithm only works for certain conditions - your object should be made up of just one single surface, not multiple surfaces (like a cube has 6 surfaces in it normally, this won't work. You have to create a special cube that is made up of just one surface instead). And also the surface should not be trimmed, like it should not have been run through booleans or those types of processes. That's because you want the UV space to be completely covered by the triangulation which is only the case for untrimmed surfaces.

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I'd love to get my paws on the source, I want to make a Managed C++ interface for it (bring it into .Net). I want to add it to the SculptPreview mod I'm working on. -- Strife Onizuka 13:04, 9 May 2007 (PDT)

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The latest version (besides the download being slightly corrupt, nothing a little hex editing doesn't fix) crashes on most (if not all) of the OpenNURBS sample files, [1]. Not to mention that it sometimes exports things in a crazy fashion (example: v3_SphericalSpiral.3dm). I wish it would output at 128x128. -- Strife Onizuka 15:16, 9 May 2007 (PDT)

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Ouch... well, you asked for the source, i guess all you need is this : here it's based on the OpenNURBS example_read, and has the same Dependencies. The source is a real Mess... but you asked for it :P I guess you will rewrite it, its quite simple. --Cindy Crabgrass 15:24, 9 May 2007 (PDT)

You make it sound worse then it really is (or I just have a high tolerance for bad coding). It's allot simpler then I had expected. -- Strife Onizuka 19:27, 9 May 2007 (PDT)

Yes the OpenNURBS Library does all the hard work... i wished i could do the same to .obj Files, that would be a lot more useful, but the more i learn about it, the harder it seems. Rebuilding the Topology of a random Mesh to a Sculptie - someone will do it sooner or later.--Cindy Crabgrass 19:56, 9 May 2007 (PDT)

Converting an arbitrary mesh to a sculptie would be a hack, it would require an alg willing to hidden polygons. Not to mention having to refactor the vertices. Then comes the mess of having to convert textures because of the change of UV cords. It wouldn't just be hard work, it would be a nightmare that would result in imperfect results (as a programmer and a bit of a perfectionist, that turns me off). I do not envy anyone taking on the task. -- Strife Onizuka 06:35, 10 May 2007 (PDT)

Just for Fun, i improved my old obj2sculpt a bit, now it 'resamples' from the UV coords to the Sculptie. The results are not exact, because the interpolation within a Triangle (the Barycentric Stuff) is still missing. At least, it finds the correct Triangle in the input Mesh - so it works OK on Huge .obj Files. The real Pain is unwrapping the Mesh to a closed UV Map... Link to obj2sculpt (Experimental) --Cindy Crabgrass 22:39, 10 May 2007 (PDT)

I can imagine the unwrapping would be. Could you explain or point me to a resource about what you are talking about with regards to the barycentric stuff, I'm unsure what it means (I have a couple ideas but neither are pretty). -- Strife Onizuka 01:40, 11 May 2007 (PDT)

In the future, could you zip and attach the file to a post on the forums? -- Strife Onizuka 01:41, 11 May 2007 (PDT)

OK, i will try that. I didnt trust the Atachment Function to handle my Files, but these one-click-Hosting Services sure make a lot of Trouble. Sorry. --Cindy Crabgrass 07:23, 11 May 2007 (PDT)

Now the Barycentric Stuff is implemented. It works like this : I calculate the Barycentric Coordinates of the 'Ray Hit' in the input Mesh Triangle. The output Vertex Coordinates get interpolated by these Coords. Barycentric Coordinanates are like weights on the 3 vertices, they point to a kind of 'center of weight' somewhere in the triangle. the Sum of them is always 1. This stuff is used in Raytracing and other nice Algorithms.

3ds max

hi, does this work with files saved in 3ds max? --Caleb Francis 06:03, 10 July 2007 (PDT)

3ds != 3dm (that means: No) -- Strife Onizuka 00:35, 11 July 2007 (PDT)

oh, woops... thank you --Caleb Francis 04:24, 11 July 2007 (PDT)

Program not working at all for me

I just downloaded 3dm2sculpt and tried it with a very simple object I made in Rhino (a barrel), but I get an error message saying the program won't run because the configuration is incorrect and needs to be reinstalled. I tried both methods of dragging and dropping a file and using the command line... neither way gets me anywhere. I have the program in the same folder as my 3dm files. Is there something else I should try?

Some say the 3dm2sculpt.exe doesn't work, try this.

I posted on the MOI discussion forum about the .exe not working and they came up with this solution. Download this, http://www.microsoft.com/downloads/thankyou.aspx?familyId=200b2fd9-ae1a-4a14-984d-389c36f85647&displayLang=en DON'T REMOVE THE 3DM3SCULPT.EXE just download that and install, the use the drag and drop. It seems to work ok, but it does split it into lots of separate sections, if anyone knows a way around this, please let me know.

Anya Southard

I thought that this may be a little bit helpful to some people.

Hi Anya, no there isn't really any straightforward way to convert an entire model with many parts into just one single TGA texture map.

Fundamentally the sculpt map is a type of object that is kind of like a rectangular rubber sheet. It always has a kind of rectangular layout to it, and different points along the sheet can be stretched into different 3D locations to form a shape.

An OBJ file is not structured like one single sheet - usually OBJ files are made up of many different little polygons, without the restriction of being arranged in a sheet type layout.

If you create one single surface in MoI, like the result doing a loft or a sweep, then that single surface does have a rectangular layout to it, and it is this kind of single surface that the 3dm2sculpt conversion program is really targeted at converting over to a sculpt map.

If you use other tools such as booleans or trimming, that will make an object that is made up of many trimmed surfaces instead of just one single surface sheet - something like that will not convert very well over to a sculpt map.

Hopefully in the future Second Life will support more general polygon mesh structures like a regular OBJ file has. It is difficult to create a complex object just out of one stretched rectangular sheet.

- Michael From the MoI Forums.

I will say that Michael has been very helpful and very understanding. I am completely new to 3D working and has answered all my questions that I have asked on the forum. MoI is a very easy to learn and the staff (Michael included) have been very helpful to a complete newbie in this sort of programming. Thanks guys.

Michael has articulated it well. There are many difficulties inherent in doing such a conversion. The problem is how do you stitch the different sections together? If there is a hole in the center of a face it can't be stitched together at all. The stitching process is the wrong approach altogether. The correct method is to refactor the mesh... which turns out to be more difficult then any flawed stitching technique but not impossible. -- Strife Onizuka 19:19, 4 October 2007 (PDT)

the download links are not working

I have tried all links to download and they are not working. Missa Morahan 04:01, 21 June 2009 (UTC)

I feel better

For a good while I was devoting a large amount of time to perfecting this but I lacked the math background. In reading the news tonight I came across an article about a Russian Mathematician who had  solved the  Poincaré conjecture. Wish I had read about it sooner, it's the solution. -- Strife ^{(talk|contribs)} 06:34, 16 April 2010 (UTC)