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bboyBladeJ

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About bboyBladeJ

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  1. Shadow Maps and Directional Lights

    What exactly are you trying to do? Because I believe that all you need is come up with any usable 3D position for the directional light, which wouldn't mess up you further computations. And this can be easily done by computing a bounding sphere for the whole scene and then setting the light position to any point outside the bounding sphere. Or if your scene is static, you can even set the position to a constant. Watch your precision though ;-) George
  2. Fast Global Illumination

    Can you elaborate on how exactly you compute indirect illumination? Because "radiosity-like" algorithm doesn't give much usable information. Thanks, George
  3. Maya UV + vertex count

    The number of UVs depends exclusively on the mapping you apply to your model. Since some mappings infer shared UV coordinates the total number of UVs can be smaller than the number of face-vertices. If you create a cube in Maya and launch the UV Texture Editor, you'll get this: If you count the number of UVs in that picture, you'll get exactly 14. As for the code - look at Maya API documentation, primarily the MFnMesh class. It describes everything you need to know in order to extract UVs. It takes couple of hours to code the whole thing. George
  4. Let's say I'm working on a research project with and would like to try out how Direct3D 10's new features can be of advantage to me (and I do believe they can be). Is there a way one can obtain working samples of nVidia's G80 or ATI's R600 cards before they are avaiable on the market? I'm affiliated with a computer graphics group at a university in Florida. Do you guys know if ATI or nVidia is able to support research work carried out at universities or do they only provide samples to big studios such as ID, EA or Ubisoft? Thanks a lot, George
  5. Line and curve sampling

    What do you need this for? Why would you want to sample a Bezier curve at many locations and then try to reconstruct it using the sampled values? Each Bezier curve of degree N can be represented using a finite set of (N plus 1) control points and you never need to reconstruct from sampled values unless you cannot store the control points (which is a scenario I cannot even try to imagine). I believe it is possible to reconstruct from sampled values, but I'm sure this would lead to many numeric and rounding errors. Just use the control points. George
  6. Hi everyone, having an MSc. degree with specialization in Computer Graphics I was wondering if it pays off to obtain programming certifications such as the ones offered by Brainbench.Com. I consider myself to be a very good programmer, but that's not always sufficient to get a job. I'm talking about getting into the game industry as a programmer and I'm willing do to a lot for it. 1) Does anyone have particular experience when it comes to taking certification into account during the hiring/interviewing process? 2) What are the most respected certifications available for programmers? Thanks everyone for responses. George
  7. Volume Texture Lighting

    I'm just browsing through that material as well, because it interests me a bit. There's a great PPT presentation on volume rendering illumination on that page. It explains how gradients can be used instead of normal vectors to compute illumination. I believe that's what you're looking for. Cheers, George [Edited by - bboyBladeJ on July 5, 2006 9:09:43 AM]
  8. Volume Texture Lighting

    I believe you are talking about illuminating volume renderings. I suggest you look at the following link: High-Quality Volume Graphics on Consumer PC Hardware These are Siggraph course notes, look especially at the section about illumination. There's a lot of research going on in this area, but the stuff is generally not easy. In volume rendering no vertices are used to compute face normals, but instead illumination is computed on non-polygonal isosurfaces. Hope this helps at least a bit, George
  9. maya exporter for .x file

    Hi, have you looked at the DirectX SDK ?? There's an .X file exporter for Maya already included. I used it several times and it works great. However, your mesh needs to have correct topology. bboyBladeJ
  10. Hi, referring to my experience in computational geometry one solution to this problem are Higher Order Voronoi Diagrams. Given a set of N input points S in 2D and an arbitrary query point X, a Voronoi diagram allows you to find the point in set S, which is the nearest neighbor of the query point X. See the figure as illustration. Higher Order Voronoi Diagrams generalize this concept to allow for searching for M nearest neighbors, not just one. What you can do is just keep querying the structure for farther nearest neighbors until you exceed the distance limit. Once this happens, you don't need to search anymore, because all other points are farther than the last point. The disadvantage of this approach is that the implementation is not easy at all. It might take several days to code this, but I believe it's worth the time. Here's an applet which demonstrates the idea behind first order Voronoi Diagrams Voronoi Diagram Applet. Hope this helps, bboyBladeJ
  11. interpolation of 3 points

    Well it's not hard to derive at all, just play with the math a bit: having three points a,b,c, an internal point x can be calculated as: x = a + alfa * (1 - beta) * (b - a) + beta * (c - a) where 0.0 <= alfta, beta <= 1.0 The way to get it is to use simple 1D interpolation equation x = y + beta * (c - y) and substitute y with y = a + alfa * (b - a). Hope this helps bboyBladeJ
  12. maths - sin between vectors

    ||A x B|| = ||A|| ||B|| sin(angle) - cross product ||A . B|| = ||A|| ||B|| cos(angle) - dot product
  13. Hi guys, I need to determine the size of the video memory from a Managed DirectX application. I know that there is an AvailableTextureMemory property of the Device class, but this does not help, because it includes the AGP/PCIe memory. What I need is the size of the physical video memory on the card. Any ideas how to do this? Thanx for help bboyBladeJ
  14. Divx decoding (Windows)

    Yeah sorry, DirectShow is right:-)
  15. Divx decoding (Windows)

    I solved a similar problem last week. However, using C# and Managed DirectX. What helped me was something called the MediaDetClass class and DirectPlay. Especially DirectPlay might be useful in your case, because it supports direct rendering to textures.
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