Extrude along spline in 3d studio max

As many of you I do enjoy working with an “extrude along spline” tool.
It makes your modeling so much faster in some cases, and it has
flexibility to achieve various results fast. I found it very good when my
task is not very constrained, when I work with something that I can change and create at my will.
But Some time ago I needed to do something more precise. To be exact i had to
do some lines on a sphere surface. I did remembered nice tool we have in NURBs arsenal which is called “create cv  spline on surface”. Now that i had my splines on a surface i needed to use them as splines for extrusion in my model.  And then I had some troubles with extrude along spline tool.  It just doesn’t seem to actually follow given curve, or to be more precise, the result is same as the curve, but its orientation is all wrong.
And then I had to find how to fix it. So if any of you happen to have same problem
here are some screen shots with a problem and its solution.

 

object and the spline
object and the spline

 

Just a picture of an object and a curve.

extrusion
extrusion

 

 

 

 

 

 

 

 

 

 

 

 

So we select faces and go to extrude along spline, and we choose our spline.

 

aligning
aligning

“Align
Aligns the extrusion with the face normal, which, in most cases, makes it perpendicular to the extruded polygon(s). When turned off (the default), the extrusion is oriented the same as the spline. To Face Normal, the extrusion does not follow the original orientation of the spline  it’s reoriented to match the face normals, or averaged normals for contiguous selections. The Rotation option is available only when Align To Face Normal is on.”  description from 3dmax help file.

 

rotation
rotation

 

“Rotation
Sets the rotation of the extrusion. Available only when Align To Face Normal is on. Default=0. Range=-360 to 360.” again, from 3dmaxs help.

make it first
make it first

 

So here we

select the vertex which is closest to extruded polygon so we can make it “first”

wuala!
wuala!

 

 

 

 

 

 

 

 

 

 

 

So we have it. Now our extrusion actually follows given spline. This seems to solve my problem. Hoope it helps you too.

 

 

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VideoTrace – 3D modelling using real video

It was quite a long time that i found this video somewhere and it did impressed me.  Here we are talking about 3d modeling. actually about very fast skechup like 3d modeling interface based on filmed video. Now definitely it cannot be a solution to all modeling needs, but one could benefit from such fast prototyping tool. please have a look at the video, it shows everything rather clearly.  If anyone knows anything about future of this product / research, please drop me a line in coment,

thanks.

implicit surfaces, aka blob mesh, and metaballs. PART II

So as we can see in a previous post (if we read comments) there where some concerns about my proposals validity. Mainly Delt0r raised some valid questions. therefore i have been struggling to improve my initial idea, and here is what i came up with. Now, its still has some flows. and questions. but its for u to judge, sins i have no clue about maths, and here its quite important, i mean the math.

so the idea is this.

A. we have a mesh. *(base mesh) which we will use to to determine where the “blobs” appear.

B. we will get the normals of each vertex.

c. then the slicing planes should be generated. (here u can look at my old post or drawings beneath)

here comes the first problem. what i want to find out – is there a way to limit this “slice plane’s ” effect. here no one will understand me, so lets have a look at the picture:

screanshot of blobmesh section in max
screen shot of blob mesh section in max

Here we have a blob mesh, and a slice tool. the white plane is a slice plane, and green line is outline which is generated. the problem is that the green outline goes out of boundaries of slice plane, and correct me if iam wrong but iam sure algorithm behind this procedure works this way. so what we would like to have here would look like this:

blob mesh, facke intersection
blob mesh, fake intersection

Ok how to do it ? i have no clue. It might require rewriting all algorithms behind this operation, or doing it old way, and then subtracting unneeded parts. which is probably easier.

so now lets imagine our slicing works like we want it, and lets move on.

so in order to understand my “hand” drawings here is another diagram for explanation:

normals
normals

so this diagram shows a mesh we will be thinking about. in next drawings i draw only 3 vertexis out of this mesh. In this image we can also see averaged normals (left)cos normally each plane is plane :) so all 4 vertexies should like in image on right. but we can get average values.

how to make planes
how to make planes

you can enlarge this image to see better. but the idea is to make planes for each vertex separately.

so here as well we have problems. first of all we would want to arrange planes so the would make a “continuity” i mean they would go like this: /\/\/\/\/\/\ shit i have no idea how to explane…. look at the drawings again. chm…. please tell me if anyone understands what i am talking about ? ah? anyone?

so and last step would be to “weld” vertexies who are very close to each other.

again i wonder how easy it would be to make so many “restricted” planes for slicing.

but from what i understand, if it would work it could improve mesh topology or?

any ideas?

implicit surfaces, aka blob mesh, and metaballs.

ok, its a long time. so some thoughts on implicit surfaces and their topology. so why do we talk about it in first place, its becouse of its ugly topology. metaballs are so cool, but hardly usable in animations and in other fields cos of irregular and ever chaging mesh topology, so what do we do? lets think.

first, a description of implicit surface as i understand it.

2.2.3 Implicit surfaces (Bloomenthal 1987)

Implicit surfaces are also known as “Metaballs”, “Blobbies” or “Soft objects”.

Implicit surface is a technique first introduced by Jim Blinn in 1980. The idea is to have control objects, which determine the resulting surface. Each control object generates a sphere around itself. When two or more controller objects are close together, the resulting surface will “melt” together. So instead of two spheres one will have two spheres which are connected and form a “blobby” single surface shape. How much the resulting surfaces blob together is a result of distances from controlling objects and of weights of these control objects. (Maestri. 1999 43-44)

so i had few ideas on the matter. pls look at a picture and tell me what u think.

ok. now as far as i understand the poligonization of such mathematical substance :) as metaball, it works like this (and pls correct me if i am wrong) the algorithm “checks” certain points in worldspace to see if that point is in or outside of this mathematical descriptio0n of metaballsurface. so basically, user determines “resolution” or level of detail he or she wants, and based on that, algorithm generates planes, to see where are boundaroes of this object in that particular plane. and planes are generated in x, y, and z. so pls look at picture beneath. so what i thought of is, why user is not able to determine how these planes are distributed and aligned? why dont we have such simple control as in uv ordinates, u know we would choose box, cilinder, sphere just like in uv layout (imagine box uv layout as a traditional plane distribution for imlicitsurfaces).

so people who have read, and understood, some of papers about implicit surfaces, including old john blinns texts, tell me do i bulshit or that could be a very small step towards better topology?

and some links to read more: here

and as usual link to my other website here

4.3.1 Tools for Automatic Tree Hole Generator

here some tools will be presented which are in 3dmax. the same tools are probably in all 3d modeling programs but sins i am familiar with max, i will kind of talk in its terms.

……………………..

In order to describe this aspect of hole generation as part of a proposal for an automatic tree generator it is important to introduce some tools related to this process.
These tools are available in almost all 3d modeling applications and are called insert polygon, connect, extrude and chamfer.
The Insert polygon tool shrinks a selected polygon along its plane, and adds four additional polygons. Using this strategy, there is an original polygon as a boundary, and five new polygons inside. The middle one has exactly the same outline as first one, onto which we applied the tool, and others are made by connecting edges of the original polygon and new one which is smaller. This tool works not only with quadrilaterals, but also with any given polygons or polygon groups. To better understand the way this tool works please look at figure 29

Fig 29. screenshots from 3d studio max.
The Chamfer tool works with vertices. This tool can be applied on a selected single vertex or multiple vertices. In order to understand the chamfer tool, imagine a situation where one vertex is connected to four other vertices by four edges. After the chamfer tool is applied four new vertices are created on edges connecting the first original vertex to its surrounding vertices’s. The distance is always specified by the user and then the newly created vertices are connected with new edges. The original vertex which was selected in a first place is
erased. For clarification see figure 30.

Fig 30. screenshots from 3d studio max.
fig 30. shows selected 4 vertices (top) and resulting mesh structure after chamfer operation (bottom)
The Connect tool connects selected vertices by creating new edges. The Extrude (Landrenau 2005) is a tool which moves a selected polygon or polygons along a normal and creates new polygons that form the sides of the extrusion, connecting the selection to the object. For clarification see figure 31.

Fig 31. Picture taken from: Eric Landrenau. 2005. Crystal-Like Geometric Modeling. Thesis of Master of Science. Texas A&M University

Now that you are familiar with the tools necessary for a proposed automatic hole generator, what follows will be two approaches for the detection of where a hole a could be generated. Once this is described the proposed steps for the generation of a hole will be outlined.

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selection tools in photoshop.

So today i had to edit this picture, look below.

As u can see its kind of a blue prind, well to tell u the true its a model i have to texture, but i whannted to heand draw texture o i decided to print outlines or wireframes of 3d model to have them as guidelines. Now lets look at the area marked in read. this is some sort of grid, which is actualy remains og a grid plane in 3d max, it was on, when i did a viewport grabing… well its kind of anoying so i decided to get rid of it. and clean the picture in general, so i would have only the lines i nead.

No how would one go about cleaning such lines in photoshop? selection by color will not work, all lines are black.

laso tool? long work…. lasso tool whith magnet, or whatever its called, the one which reacts to contrast and finds “outline”. this one is kind of best. but still hard to use in this case. so i remembered how in max we can select loops and rings of edges, i thought coudnt we impliment this in photoshop? ofcourse it would serve only in very limited cases, but still. I think it shuld be done using basis of this magnet poligon laso. it would detect edges or contrast basicaly between pixels, and it could just folow a row of pixels. it shuld determine the direction of pixel row, and then if dyrection change, pixels are not selected… might be dyrections could be somehow determined by user.. whith some simple mouse movements.. dono.. but what i whanted to say it took me like 10-15 minutes to get rid of unneaded lines… could have been done faster..

any ideas?

photoshop

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