# NeXius

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1. ## Solving the quintic

Thanks AP, that link has a great explanation Looks like just what i need I think I'll give up on the bezier approach
2. ## Solving the quintic

Hi I've got a problem that involves solving a quintic polynomial.. So I started googling for ways to do this, and was surprised to find the large number of different methods to choose from One method I like ( mostly because it's so easy to understand ) involves estimating the function with a bezier curve and using some properties of the bezier to find the roots. (I found it in the first of the Graphics Gems series) So I implemented this but am stuck at converting my function to a bezier.. The explanation in the article seems to be flawed. Anyway, my questions are: 1. What's a good way to solve the quintic? 2. Alternatively can someone explain how to estimate a function as a bezier curve? ( would save some code re-writing ) Thanks for your time.

What's the error message
4. ## Wanted: The perfect OOP application

OGRE (Object oriented Graphics Rendering Engine? Something like that.. ) Personally I found pouring through its code quite informative. It's got good documentation as well.
5. ## Distance to bezier surface

Quote:Original post by arithma Let the bezier by a function (f(u,v)) returning a point for two parameters Let P be the point of interest Calculate Analytically Distance from f(u,v) to P You can apply a square on both sides of the equation if that simplifies the equation. Ok, I'm with you so far Quote: the distance (and u and v) are determined by solving for the partial derivatives with respect to u and v are equal to zero. If there are generally more than one solution, you can compare them... I'm not sure what you mean here. I think the distance equation you mentioned will be a function of two variables, both variables having a max exponent of 3. I'm not sure how to solve something like that. Btw, I implemented Eelco's solution (thx again) and it seems to work pretty well, but like I said performance is an issue so if there is an analytical/better solution I'd definately give it a shot The deadline for my project is in less than a week however so I won't be able to investigate your suggestion until after that (The project involves creating a voxel field around a bezier surface)
6. ## Distance to bezier surface

Performance is a bit of an issue but that's a lot better than just brute force, so thanks I will look into bezier clipping..
7. ## Distance to bezier surface

Hi I've got a project and it requires that I figure out a decent way to determine the (u, v) for the closest point on a bezier surface to any given point in space. An idea that I'm working on: The points on the surface that are going to be the closest are going to be either a point on one of the edges or an internal point who's normal is collinear with the direction from the surface to the given point. This seems correct to me. So I thought I would see how far I could take that idea analytically. I got this equation: du * ( p - o ) + dv * ( p - o ) = 0 Where du and dv are the partial derivatives of the surface, p is the point on the surface and o is the given point in space. If I expand this I get a cubic equation of two variables (surprise) which looks impossible to solve. Am I on the right track here? I do not want to just tesselate the patch and consider each point but I can't think of any other ideas. Sorry for the long post Any help is much appreciated
8. ## One More Noob Question - Templates

I only chose .inl because VS.NET highlights the code the same way
9. ## One More Noob Question - Templates

What I do for all my classes is create a header file, a cpp file and an inline file ( .inl ) I put all my templated classes into the inline file and it works fine Maybe you forgot to include the 'inline' keyword?
10. ## Meta-cubes, meta-cylinders and the like

Ahh ok I understand Thanks What kind of effects can you get from transforming space? Ellipsoids and boxes come to mind
11. ## Meta-cubes, meta-cylinders and the like

Hi I understand how meta balls work, but as for meta-cylinders, meta-cubes, etc. I'm not sure I haven't been able to find any topics on these other forms anywhere on the net, so if someone can explain it to me, it would be much appreciated Thanks
12. ## Objects that need to know... (part 2)

While you're explaining that, could you explain why you have more than one PollingEngine? You said to facilitate 'layers' but I don't understand what you mean by this I ask because I have a similar system but with only one 'PollingEngine' Thanks
13. ## Objects that have to know about other objects (design issue)

Can you describe your EventManager in more detail? Do classes 'register' for events? How do you represent the event ? etc I'm very interested to know Thanks
14. ## Terrain editor - Common approaches?

Very nice links, thanks I tried all of them, and they are all quite nice, but I think I'll still implement my own. I have time, and don't consider what I'm getting done here as important as what I'm learning. Plus, I hate the controls in all of them
15. ## Terrain editor - Common approaches?

I think I will go for both approaches like you suggested. I just finished adding a text system and a console window to the game so I could easily add some clunky controls to tweak any problems with the levels... and I'll need an external tool (C#, now that it appears possible) for most of the editting Quote:Original post by Undergamer Their is a tutorial on setting up MFC to do this, however you might find it easier (if you have the tools.. i.e. VS.NET or the compiler package and a free ide) to use C# to render your terrain while you edit it. I think C# retains the power of C at the expense of being as easy to work with controls as in VB. That said, you can do this in any language but C# is probably the fastest route. I'm using VS.NET 2003, so I have easy access to C#. I'll start looking at ways to take advantage of my DLL, but if you have any links already, I'd be happy to hear them :) Thanks for the help