2,379 reputation
628
bio website linkedin.com/in/teodorc
location Bucharest, Romania
age 29
visits member for 3 years, 3 months
seen 1 hour ago

Mathematics Researcher. Main interests:


  • physics based animation (deformable objects, kinematics)
  • mathematics of CG applications (simulation, games, etc.)
  • shader programming
  • discrete differential geometry (manifold properties)
  • robotics

While you're here, please stop saying these two things

  • quaternions avoid gimbal lock
  • premature optimization

why?

  • gimbal lock is related to a mechanism, quaternions are just an algebraic/geometric description of an angle-axis rotation. So they do not avoid it since the mechanism itself cannot.
  • if it's an optimization, if it's common sense, just implement it! Better do it now, than to look for it desperately later.

Jun
29
reviewed Approve How closely can a game legally resemble another?
Jun
29
reviewed Approve Updating object positions after screen moves. Is there a better way?
Jun
24
reviewed Approve Pixel Shader, YUV-RGB Conversion failing
Jun
24
reviewed Approve How do you make Direct3D work in a browser?
Jun
24
reviewed Approve Implement car handling in Phaser
Jun
20
awarded  Nice Answer
Jun
19
comment How to simulate cylinder shape in collision detection?
@JamesAMD I'm not sure about Bullet, but last time I meddled with Havok, I think the actual collision between two cylinders boils down to treating them as convex solids and using GJK (which is indeed more expensive). But since Havok is not open source, judging by how the cylinder shape is formed, one can only hypothesize that GJK or anything else as general is the way to go. See here: transporter-game.googlecode.com/svn/trunk/inc/physics/Physics/…
Jun
19
comment How to simulate cylinder shape in collision detection?
@JamesAMD to answer your question accurately, I should look into specific implementation details of those collision queries and preferably benchmark them on different processor architectures. Looks like finding the exact collision point is tricky, involving a bit of conjugate gradient search, as detailed by Eberly: geometrictools.com/Documentation/IntersectionOfCylinders.pdf . Aside from that, as I said, one needs benchmarks to see how much the "early-out" tests help avoid the "expensive" part :).
Jun
18
reviewed Approve Is my collision-free location script working?
Jun
15
reviewed Approve Grid Based AI Pathfinding
Jun
15
reviewed Approve How to create gui image with script
Jun
11
comment Quaternion Slerp and Lerp implementation (with overshoot)
This is a nice little gem.
Jun
11
reviewed Approve How to draw a sprite without black transparency key?
May
24
reviewed Approve How to detect if I click on an object (2D) using Raycast?
May
22
comment Can I render 3D objects in Ray Casting engines?
Probably objects as NPCs and other things were displayed as sprites since it was easier to represent them as quads anyway without having to complicate the ray cast queries. The term istelf, ray casting, is broad (see en.wikipedia.org/wiki/Ray_casting). Are you referring to non-recursive ray tracing in this context? The very short answer to your question is a definite yes. The details and drawbacks are sufficient to fit in a (large) book discussing ray tracing and its history and related methods.
May
11
reviewed Approve Calculating the rotational force of a 2D sprite
May
10
awarded  Taxonomist
May
6
reviewed Approve 2D HLSL World position
May
6
reviewed Approve Is it possible to retrieve shader function names associated with a technique pass using the DirectX Effect API?
Apr
29
reviewed Approve Java libgdx Game Screens and rendering tile map