The last part is no more, i substituted it for a srf4pts component that creates some sort of skin but it's still buggy. Nevertheless, your problem seems to be that you've got to set the formula components to "cross-reference" (right click on top of them to set it).
You'll encounter another problem. If you delete the last point parameter you've got, the point cloud will seem fine. But if you leave it as it is, you'll get like a grid of points projected on the XZ and XZ axis that you don't want. This is because there are some cases that the formula return a "null" value (when there should not be a point), but when you transfer the data to the point parameter the "null" value is converted to "0". You can filter this points using the cull pattern component linked to a function component with the following expression "(p.x ≠ 0) and (p.y ≠ 0) and (p.z ≠ 0)" where the input of the function component is p (the points). I think i explained my self horribly, so i'd just delete the point parameter at the end of you definition for now and set the formula components to cross reference. On Nov 21, 4:05 pm, klint <[EMAIL PROTECTED]> wrote: > This is so cool. visose - it is incredible that you can create this > things. I am quite new to this forum and to GH but I couldn't resist > trying the mathsurfaces, and it's really a matter of copy and paste > from K3DSurf, even though in some cases I haven't figured out how to > set the proper range. > > Anyway I tried to follow your solution for the Schwarz surface but I > wanted to ask 2 things. > > As you can see in this > screenshot:http://picasaweb.google.se/lh/photo/RpDHwCRaBECD3718zd2PNg > I didn't know what the first and last parts where, so I set the first > interval to A:-4 B:4, I think I got the other parts right, but could I > ask what the last part is? > > /Lars > > On 21 Nov, 15:06, visose <[EMAIL PROTECTED]> wrote: > > > I'm not sure what would be the best way to create isosurfaces in > > grasshopper (I just learned about them). > > The simplest way to visualize this shape would be to create a 3D grid > > of points that range from -4 to 4 in the 3 axis and then cull this > > list of points using the expression cos(x)+cos(y)+cos(z)< 0, since the > > points that lie inside the volume will result in < 0. The points > > oustide the volume will result in > 0 and the points that lie in the > > exact boundary of the surface will result in = 0. > > This will create a point cloud that will appear to have that shape > > with just a couple of components. > > > If you want to find out the boundary, you have to "solve for x". > > This is what i did:http://grasshopper3d.googlegroups.com/web/schwartz.jpg > > Since there are 3 variables, I create a 2D grid of points in the XY > > plane that already gives me 2 of the variables, and then I solve for > > the third one. > > The problem is that the third point may have more than one solution, > > but grasshopper only solves for one of them, so it results in > > something similar to the "drape surface" command in rhino. > > What I do is "drape" four 2d grids of points each on a different side > > of the object. What I get is a list of points that lie in the surface > > of the object. > > I don't know if there is an elegant way of constructing this with nurb > > surfaces. Meshing would probably be better. > > > - Btw there's a part of the definition not shown on the screenshot > > that creates lines between all the points and filters the ones that > > are over a given length, I don't recommend using this. > > > On Nov 21, 9:56 am, rpict <[EMAIL PROTECTED]> wrote: > > > > thanks alot visose for sharing the mathsurfaces stuff. > > > > there are a lot more formulas in explicit polar coordinates within the > > > k3dsurf package. > > > you can just paste and copy them into grasshopper mathsurfaces. also > > > the klein bottle works :) > > > > X():(3*(1+sin(v)) + 2*(1-cos(v)/2)*cos(u))*cos(v) > > > Y():(4+2*(1-cos(v)/2)*cos(u))*sin(v) > > > Z():-2*(1-cos(v)/2) * sin(u) > > > [u]:0, 2*pi > > > [v]:0, 2*pi > > > >http://k3dsurf.sourceforge.net/ > > > > this leads me to another question: > > > the k3dsurf package contents also isosurfaces in cartesian coordinates > > > F(x,y,z,t....)=0 > > > e.g. the Schwartz surface: cos(x)+cos(y)+cos(z)=0; x,y,z=(-4,4) > > > does anyone know how to set up mathsurfaces in this format? > > > > -rpict
