Lambdacerro

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About Lambdacerro

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  1. Yeah after some trial and error got it working, basically i provide the player position as the camera position and the player position + light direction as the lookat vector so the shadow maps follows the player, i have a bug related with the moment each thing is update making the shadow jitter a bit but is something i have to investigate.   Thanks anyway 
  2.   Thank you for the answer, this helped me to clear out the projection part, i guess i would have to construct the ortho projection every frame based on the user camera frustum so the ortho camera always "gets" the area visible by the player.   I still dont know how the view matrix on this case works, do i need to set te position of the camera in the "center" of the frustum bbox? what about the LookAt vector? Honestly i never got the idea of what exactly does the view matrix and how the LookAt vector works (its an absolute position? can it be a normalized direction vector?)   About the bug, well i didnt wrote the library as it was taken from the Irrlicht engine, i will report the bug to them   Thanks!
  3. Hello,   Im currently in the process of implementing shadow mapping on my engine, im using a deferred renderer for now and works just fine, my main issue comes to implementing directional lights.   I've managed to setup a ortographic matrix and multiply it with a view matrix to obtain a camera who can render the scene and draw proper shadows, the problem arises in the fact that not the entire geometry is covered in the camera range.   The solution i've read is to create the camera based on the user-controlled camera frustum, however, i do not quite understand how the ortho projection works, mainly what each parameter means, right now im using a function who takes 4 parameters, this is the code (im using the irrlicht math library for my engine as i was used to it already).   template <class T> inline CMatrix4<T>& CMatrix4<T>::buildProjectionMatrixOrthoLH( float widthOfViewVolume, float heightOfViewVolume, float zNear, float zFar) { AX_ASSERT_IF(widthOfViewVolume==0.f); //divide by zero AX_ASSERT_IF(heightOfViewVolume==0.f); //divide by zero AX_ASSERT_IF(zNear==zFar); //divide by zero M[0] = (T)(2/widthOfViewVolume); M[1] = 0; M[2] = 0; M[3] = 0; M[4] = 0; M[5] = (T)(2/heightOfViewVolume); M[6] = 0; M[7] = 0; M[8] = 0; M[9] = 0; M[10] = (T)(1/(zFar-zNear)); M[11] = 0; M[12] = 0; M[13] = 0; M[14] = (T)(zNear/(zNear-zFar)); M[15] = 1; #if defined ( USE_MATRIX_TEST ) definitelyIdentityMatrix=false; #endif return *this; }   I dont know what exactly each parameter means when it comes to projection, i'm also not quite sure if i need a view matrix to create the light camera, maybe someone can help me with this.   Thanks!
  4.   Thank you for the answer, the AA BSP Tree might be a good idea.   I already thought about how to filter dynamic objects just in the same way you said, basically each entity would know in which cell its located so the entity knows what's visible (useful for IA), same as player basically.   My idea to compute the PVS was to go raycast from each cube corner to all the other cubes, main problem with this is that it will be really expensive based on the fact that each cube have 8 childs, i was thinking to just raycast to the "bigger" cubes (either by area or polygon count) this way i would be able to still skip rendering of hidden geometry and not take ages to compute the visibility.
  5. Hello guys,   Right now i'm working on a game engine for a game i want to make, this is mainly for research and learning purposes.   I have most of the rendering base code done, loading meshes from a custom format aswell as materials and other stuff, however, in the last days i've been doing some research about what space partitioning method should i use for my world geometry.   I've been reading about KD-Trees, Octrees (and it's smaller variants) and BSP Trees, out of the three i guess i will stick with Octrees because it allows both outdoor and indoor efficient culling of geometry (or that's what i understood), the game will be mainly indoor but because of the nature of the project i wanted some generic way to make both types of scenes.   I've got the concept of octrees pretty well and i dont think i will have problems when implementing them (Im a self-taught graphis programmer), however there are some concepts that i dont get a clear view when i think about them, mainly precomputed visibility of nodes and what would be the most efficient way to render each visible node.   For the first i thought of the hardcore way, for each node check which nodes are visible (just like portals), this is kinda heavy for a complex scene but i dont mind to spend some time on precomputing visibility, the other i thought is to do the checking on the fly based on the camera frustum bounding box or the frustum planes themselves.   The other is once you determine which nodes are visible, what would be the most efficient way to render them.   The first approach i thought was to build a list of indices of the visible triangles and send them to the rendering API to be processed, main problem with this is that is kind of CPU intensive i guess since you would have to iterate over all the nodes, grab the indices of the polygons inside them and copy them over the active index buffer.   The second was to make a index buffer for each visible node and render each node manually, main problem with this is the memory overhead (i guess that DX/OGL uses extra memory per each created index buffer besides the memory needed to hold the indices itself) and the increased draw calls, both for the drawing itself and the switching between index buffers.   The third is to precompute a index buffer of the visible polygons for each node, same issue with memory as the second method.   I ask the help and opinion of the experts over here about what would you guys recommend me in order to create the best possible design.   Thanks!