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2
votes
2answers
773 views

How to interpolate a height-map with normals

My Task I want to interpolate a heightmap by using the normal of each nearby point of the heightmap which is calculated before. When having 4 Points before i gonna have 9 points after it. ( See this ...
3
votes
1answer
533 views

Unusual Lighting Effects - Random Polygons Coloured

I am working on creating an object loader for use with iOS, I have managed to load the vertices, normals and face data from and OBJ file, and then place this data into arrays for reconstructing the ...
5
votes
1answer
2k views

Normal transformation and homogeneous coordinates

I'm very confused about the math behind the model/affine transformation expressed in homogeneous coordinates. Reading this article, I understood that a generic vector is transformed by multiplying it ...
2
votes
2answers
1k views

Calculating vertex normals on the GPU

I have some height-map sampled on a regular grid stored in an array. Now, I want to use the normals on the sampled vertices for some smoothing algorithm. The way I'm currently doing it is as follows: ...
2
votes
2answers
234 views

A little bit confused on how to set normals in this case

I'm learning how to use VBOs and I'm following up on the tutorial at the bottom of this page. So I went ahead and created a structure Vertex to hold vertex data.(coordinates and normals). struct ...
2
votes
1answer
966 views

How do I determine the collision normal in an axis aligned bounding box collision?

I have a 3d moving box and a stationary box. I can detect collisions ok but now I would like to slide the moving box against the stationary box as a collision response. For this I need the normal of ...
7
votes
1answer
2k views

Given a plane and a point, how can I determine which side of the plane the point is on?

Given the point Vector pos = new Vector(0.0, 0.20156815648078918, -78.30000305175781, 1.0); and the plane (triangle) Vector a = new Vector(-6.599999904632568, 0.0, -78.5, 1.0); Vector b = new ...
3
votes
1answer
854 views

Triangle Strips and Tangent Space Normal Mapping

Short: Do triangle strips and Tangent Space Normal mapping go together? According to quite a lot of tutorials on bump mapping, it seems common practice to derive tangent space matrices in a vertex ...
7
votes
6answers
879 views

Does one need normals for a strictly 2d Game?

I'm starting to learn OpenGL by creating a pure 2D game. I have to decide on the format of the Vertices. Do I need a normal component? Or is this for a 2d component not needed? My gut feeling says I ...
2
votes
3answers
6k views

best way to compute vertex normals from a Triangle's list

hi i'm a complete newbie in computergraphics so sorry if it's a stupid answer. i'm trying to make a simple 3d engine from scratch, more for educational purpose than for real use. for now i compute ...
3
votes
2answers
1k views

How to create per-vertex normals when reusing vertex data?

I am displaying a cube using a vertex buffer object (gl.ELEMENT_ARRAY_BUFFER). This allows me to specify vertex indicies, rather than having duplicate vertexes. In the case of displaying a simple ...
5
votes
5answers
7k views

Any reliable polygon normal calculation code?

Do you have any reliable 3d polygonal face normal calculation code? Any language will do, I'll port it to make it work. Even if you find some code in a 3d game engine and post it here I'll be more ...
2
votes
2answers
791 views

C# XNA Normals Question

I have been working on some simple XNA proof of concept for a game idea I have as well as just to further my learning in XNA. However, i seem to be stuck on these dreaded normals, and using the ...
4
votes
4answers
1k views

How to find two perpendicular lines given a single plane

Hey guys, i was wondering how i would go about finding the perpendicular lines relative to a surface normal. For instance say i have (0,0,1) the expected output would be (1,0,0) and (0,1,0). What ...
7
votes
2answers
745 views

How do I generate surface normals?

I have quite a few debug drawing methods in my engine that can generate geometry useful for debugging, like spheres and cubes. At the moment I do not generate any normals for these shapes. Is there ...