A vector that is perpendicular to an object's surface.

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28 views

How to calculate per vertex normals? (OpenGL) [duplicate]

I am really confused and quite much thinking about how to do that? Cross product and then, normalizing is not working for me. Or perhaps, I take them all wrong. Well, please explain me that while ...
1
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2answers
75 views

Malformed/Pixelated Vertex Normals

I am trying to generate vertex normals for a given triangles/vertices list with the following code: **BASE METHOD:** private void CalculateNormals() { for (Int32 i = 0; i < m_Meshes.Count; ...
1
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1answer
43 views

Computing Normals for a displaced material

Disclosure: cross-posted on Unreal Answers, thought was sufficiently general for GameDev.SE I am currently rendering a displacement texture and, separately, a normal texture for my ocean. Is there a ...
1
vote
1answer
142 views

Marching Cubes Vertex Normals

I understand how to generate geometry using marching cubes at an isosurface, but I haven't been able to find a clear explanation on how to calculate the vertex normals for a mesh produced using ...
1
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0answers
51 views

Confused About My Code Suggesting The Normal Matrix Is Equivalent To The ModelView Matrix

I'm learning environment mapping in OpenGL by following this page. In his vertex shader, the author calculates the vertex normal in eye space with the following code: nEye = vec3(viewMatrix * ...
0
votes
1answer
92 views

Rotate a plane defined by its normal and its distance

First apologies for the amount of pictures, it's a bit hard trying to explain my problem without pictures. Hope I've provided all the relevant code. If you feel you want to know about how I am doing ...
2
votes
2answers
283 views

What is the cause of this lighting artifact on my dynamic terrain mesh?

I am generating my own terrain mesh in Unity, using pseudo-random noise to determine the height. I construct the mesh using quads, each quad is composed of two triangles. All seems to be going well, ...
35
votes
2answers
7k views

Why are normal maps predominantly blue?

Why normal maps are predominantly blue instead of a random color? I guess normal vectors of a 3D object can point in every direction, like: (1.0, 0.1, 0.5), (0.1, -0.5, 0.3), (-0.51, 0.46, -1.0) ... ...
0
votes
1answer
29 views

MD5Mesh Calculate Vertex Normals

I am writing an MD5 3D model loader to display animated models. The vertices and texcoords load in correctly, but the lighting is supposed to be smooth. I calculate per-vertex normals by looping ...
0
votes
0answers
110 views

Separating Axis Theorem contactNormal

I implemented the separating axes theorem as described in "Real time collision detection" by Ericson for my OBB vs OBB collision. Got that working. To continue with my collision response I need more ...
1
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1answer
243 views

The math of normal mapping without a dot product

As far as I understand the technical details about a good normal mapping they go like this: everything gravitates around the concept of vertex the artist provides an RGB image and an UV map, the UV ...
0
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1answer
135 views

What is wrong with my normals?

I am trying to build a cube as a composition of many quads, with each quad being composed of two triangles. All the triangles have the same size. I am dong this (instead of drawing a single cube with ...
3
votes
1answer
95 views

When using deferred rendering technique, what space should my normals be? Why?

I'm implementing a deferred shading technique and the following question arose: When storing the normals, should I transform to view space, or may I keep them in world space? Why? Will any of the ...
6
votes
1answer
324 views

Unity: Why do my normals flip during an animation?

This problem boggles my mind. I have an animation running on a face object (imported from Blender). At a few points in the animation, the normals switch direction! It causes the mesh to blink. Of ...
0
votes
2answers
199 views

How many normals are needed to have a smooth surface?

I'm trying to draw a smooth cloth surface and I have a per-pixel shader. I expect to have a smooth surface but it's not the case. I think the problem comes from my normals. The image show the surface ...
0
votes
1answer
161 views

Blender exported model has reduced quality in Unity when normals applied

I know this topic comes up a lot in forums, however I have spent the last 2 hours googling it and can not find a solution for my specific problem... I have exported this model from Blender, but when ...
8
votes
1answer
289 views

Specular banding with high specular power

We're having some issues with our ray tracing in DirectX, especially with some serious banding issues with specular. With high specular power (above 8) banding starts. I'm wondering if this is an ...
1
vote
2answers
350 views

Normals in my skinned model are not animated

I have a blender skinned mode with animation. Normals look like they are messed up. This is how it looks in Unity3D before and after animation. As you can see, my model should be lit up just like ...
2
votes
1answer
161 views

Calculating the winding and normal when programatically adding triangles to a mesh

I'm writing a program that takes a 2D planar polygon and extrudes it to a 3D mesh with a given height. I identify triangle edges that are borders of the polygon and now I'm trying to automatically ...
-1
votes
2answers
81 views

GLSL Normals not transforming propertly

I've been stuck on this problem for two days. I've read many articles about transforming normals, but I'm just totaly stuck. I understand choping off W component for "turning off" translation, and ...
0
votes
1answer
167 views

What is wrong with my specular phong shading

I'm sorry if this should be placed on stackoverflow instead however seeing as this is graphics related I was hoping you guys could help me: I'm attempting to write a phong shader and currently working ...
1
vote
0answers
63 views

Normal map lighting bug in bottom right quadrant [closed]

I am currently working on getting normal maps working in my project, and have run into a problem with lighting. As you can see, the normals in the bottom right quadrant of the lighting isn't ...
6
votes
1answer
273 views

Transforming Normals in Bump Maps

Question I have a noise texture (perlin noise, to be precise) with its value in the alpha channel and the normal components in rgb. I now wish to, on the fly, apply some function to the alpha part ...
0
votes
1answer
716 views

Transforming normal vector in GLSL

I'm looking at a basic diffuse light shader here http://en.wikibooks.org/wiki/GLSL_Programming/Unity/Diffuse_Reflection. Diffuse light needs the normal vector in eye-space, so that it can dot it with ...
0
votes
0answers
31 views

How to fix surface normal for mesh

I am developing an application that has to take STL files from users. However, some modeling programs seem to invert some of the surface normals. Basically some surface normals will be facing inward ...
1
vote
1answer
146 views

XNA Diffuse Shader Issue. Edge lighting problem. Image Attached

As you can see in this image the diffuse shading is working correctly in some places but in other places such as the the bottom of the sphere you can see the squares/triangles of the mesh. Any ...
1
vote
1answer
90 views

Why isn't the bitangent calculated?

In teh tangent space vertex attributes why is the bitangent (aka binormal) provided as an attribute instead of calculated? If the three vectors of the tangent space must be perpendicular then the ...
0
votes
1answer
183 views

Normal Map Issues

I'm experiencing a very strange result in my very simple normal map implementation on iOS 7 - OpenGL ES 2.0. I'm only using the bare parameters necessary and I'm also skipping on all the tangent and ...
3
votes
1answer
136 views

Using normals in DirectX 10

I've got a working OBJ loader that loads vertices, indices, texture coordinates, and normals. As of right now it doesn't process texture coordinates or normals but it stores them in arrays and creates ...
1
vote
1answer
154 views

Given face normal and vertices of a triangle, how to find the acyclic order of vertices?

I'm in the process of constructing a custom 3D triangle mesh. I found the vertices of the triangle in the 3D space and it's face normal. How do I find the acyclic order of vertices? If I draw the ...
1
vote
1answer
494 views

Problem calculating normals for heightmaps

So far I have been using normal avering to calculate the normals for my vertices in my heightmap, with good graphical result (see picture), however it is terribly slow. With a incresing image size the ...
0
votes
1answer
142 views

Tangent plane vectors smoothing with vertex normals [closed]

I'm trying to find a way to smooth out normals obtained from cross product of tangent and bitangent vectors calculated per face basis. I've already asked a similar question on SO, however with no ...
1
vote
0answers
2k views

How can I get this Shader for Unity working with Normal maps? [closed]

So I'm by no mean a shader coder, but I've been hacking around the last few days trying to get working a shader for the sprites of the skeletal animation tool Spine in Unity that can properly use ...
1
vote
1answer
837 views

How can I calculate a terrain's normals?

Im trying to implement basic lighting in Opengl 3+ (a sun) with this tutorial : http://www.mbsoftworks.sk/index.php?page=tutorials&series=1&tutorial=11 Im building a basic terrain and its ...
0
votes
1answer
157 views

Why are some of my normals facing away from the camera?

I'm trying to use WebGL to render some simple models, and I'm running into issues where pixels near the edge of my model are passing normals to my fragment shader that point away from the camera. This ...
1
vote
1answer
226 views

How do I draw an isoline in a shader with a triangle topology?

I have some problems with my displacment. So I would like to have a simple little isoline starting in every triangles face center of the mash pointing in the direction of the corresponding faces ...
1
vote
3answers
204 views

Is it possible to gain performance by omitting vertex normals in the GPU pipe?

I am working on a rendering problem where I want to render as many raw triangles to the screen as I can with either OpenGL or DirectX with the absolute fastest performance possible. I wondered about ...
-1
votes
1answer
292 views

Make Gameobject Stand On Surface Facing Certain Direction

I want to make a biped character stand on any surface I click on. Surfaces have up vectors of any of positive or negative X,Y,Z. So imagine a cube with each face being a gameobject whose up vector ...
2
votes
1answer
316 views

XNA calculate normals for linesegment

I am quite new to 3D graphical programming and thus far only understand that normal somehow define the direction in which a vertex faces and therefore the direction in which light is reflected. I have ...
14
votes
1answer
2k views

Normals vs Normal maps

I am using Assimp asset importer (http://assimp.sourceforge.net/lib_html/index.html) to parse 3d models. So far, I've simply pulled out the normal vectors which are defined for each vertex in my ...
1
vote
1answer
150 views

XNA Strange Lighting, Shader

Hey guys, i have strange lighting problem. I've written my own "deferred lighting" shader and this happend: Pic: Normal-Map Pic: Light-Map As long as i only use one big mesh everything seems ...
2
votes
2answers
198 views

.md5mesh normals are not smooth

I'm currently working on a project that requires me to load .md5mesh format and draw it. Following this link I've managed to load the mesh into the engine successfully, but a problem arises when ...
5
votes
1answer
222 views

Coloring Terrain By Steepness Issue

Also I am attempting to implement some simple coloring by "slope" onto my planet and to do this I take the normal mapped normal "y" component and subtract it from one. Yet I am getting some strange ...
3
votes
1answer
135 views

Surface normal to screen angle

I've been struggling to get this working. I simply wish to take a surface normal and convert it to a screen angle. As an example, assuming we're working with the highlighted surface on the sphere ...
0
votes
1answer
89 views

Normals not rotated correctly

While rendering a cube to the gbuffer (diffuse, normal, depth) I noticed something odd when applying rotations. I build a world matrix for the cube as follows: Yaw = Yaw % MathUtil.PI2; Pitch = Pitch ...
1
vote
2answers
271 views

Why are normal maps in tangent space but not in normal space?

I want to implement normal mapping in my little game engine. When getting into normal mapping, I wonder why normal maps are typically in tangent space but not in normal space? That normal maps in ...
5
votes
1answer
2k views

How to do simple bump mapping

I'm trying to do bump mapping, and I'm getting fairly close at achieving my goal. I miss one crucial piece of my puzzle to have bump mapped effect in my scene; I need to transform the normals from my ...
11
votes
4answers
11k views

OpenGL: why do I have to set a normal with glNormal?

I'm learning some basics of OpenGL but I'm wondering why there is a call glNormal to set the normal of vertices. If I create a simple triangle like this: glBegin(GL_TRIANGLES); ...
2
votes
1answer
133 views

Pixelated Normal Generation

I am generating normals for each vertex in a standard 512*512 quad. Yet when I do using the following code: public Vector3f[] normals(Vector3f[] surface){ Vector3f[] normals = new ...
3
votes
1answer
283 views

Can't get normals to work correctly with lighting in OpenGL [closed]

I'm trying to light up a simple 2d triangle with my cursor as a diffuse light source but can't seem to set the normal correctly for the lighting to look right. The function that calculates the normal ...