I am trying to integrate the Assimp skeletal animation. Following this tutorial for reference.
The change I am trying is to use fixed function pipeline.
Problem: Position, Texture Coordinates and Normal Data is fine, but I cannot figure out how the four bones and the weight data is obtained for each vertex as mentioned in the tutorial.
I think the illustration in the tutorial is quite clear on that:
Related
I'm using Assimp to load COLLADA models created and exported with Blender v2.7, but I noticed a funny issue. Whenever I apply (in Blender) transformations to a mesh in "Object mode" instead of "Edit mode", the resultant transformations apply not to the vertices I read from the Assimp importer data, but to the mParent matrix of the aiNode that contains the mesh.
That's not really a problem since I can read the vertices of the mesh and then multiply them by the aiNode's mParent matrix to obtain the vertices of the mesh in the correct position.
The problem arrives whenever I try to do the same with meshes that have bones. I don't know why, but in this case, the transformations that I have applied in "Object mode" aren't applied neither to the vertices I read directly from the mesh nor to the aiNode's mParent matrix.
Can someone explain to me how to get the correct positions of the vertices of a mesh with bones using Assimp and COLLADA models?
Maybe updating the collada importer/exporter can solve this.
I have been working on my low level OpenGL understanding, and I've finally come to how to animate 3D models. Nowhere I look tells me how to do Skeletal animation. most things use some kind of 3D engine and just say "Load the Skeleton" or "Apply the Animation" but not how to load a skeleton, or how to actually move the vertices.
I'm assuming each bone has a 4x4 Matrix of the Translation/Rotation/Scale for the vertices its attached too that way when the bone is moved the vertices attached also move by the same amount.
for skeletal animation I was guessing that you would pass the Bone(s) to the shader, that way in the vertex shader I move the current vertex before it goes to the fragment shader. If I have a keyframed animation I send the current bone and the new bone to the shader along with the current time between frames and interpolate the points between bones based on how much time there is between keyframes.
Is this the correct way to animate a mesh? or is there a better way
Well - the method of animation depends on the format, and the data that's written in it. Some formats supply you in vectors, some use matrices. I gotta admit I came to this site to ask a similar question, but I've specified the format (was using *.x files, you can check the topic), and I got an answer.
You're idea of the subject is correct. If you want a sample implementation, you can find one on the OpenGL wiki.
I am just starting out with Libgdx and having a problem adding a texture on a mesh. I can't find a working example, so I am asking for a few code snippets demonstrating rendering a mesh with a texture.
If you are using the new 3d api (only in the nightlies builds right now), you should check this: http://blog.xoppa.com/ made by the man who is working on the api right now. From using the model-meshbuilder, to loading models, adding textures and rendering shaders.
I have been asked to do 3D sphere and adding textures to it so that it looks like different planets in the Solar System. However 3ds max was not mentioned as mandatory.
So, how can I make 3D spheres using OpenGL and add textures to it? using glutsphere or am I suppose to do it some other method and how to textures ?
The obvious route would be gluSphere (note, it's glu, not glut) with gluQuadricTexture to get the texturing done.
I am not sure if glutSolidSphere has texture coordinates (as far as I can remeber they were not correct, or not existant). I remember that this was a great resource to get me started on the subject though:
http://paulbourke.net/texture_colour/texturemap/
EDIT:
I just remembered that subdividing an icosahedron gives a better sphere. Also texture coordinates are easier to implement that way:
see here:
http://www.gamedev.net/topic/116312-request-for-help-texture-mapping-a-subdivided-icosahedron/
and
http://www.sulaco.co.za/drawing_icosahedron_tutorial.htm
and
http://student.ulb.ac.be/~claugero/sphere/
I am new to game programming and graphics programming. However, I eagerly wish to learn, so I have begun building a game engine with OpenGL.
I have implemented all of the basic graphical features, and now I want to add texture support for my triangle meshes.
The only tutorials I can find for texture mapping is for a single polygon - how do I define a texture that wraps around the entire mesh?
I am loading the meshes from .3ds files using lib3ds (http://code.google.com/p/lib3ds/). Do .3ds file carry some texture coordinate data or something?
Here's a page showing an example of reading out the texture coordinates:
http://newsgroups.derkeiler.com/Archive/Comp/comp.graphics.api.opengl/2005-07/msg00168.html
However, not all 3ds files contain texture information - see warning in:
http://www.groupsrv.com/computers/about186619.html
If your models are much more complex than cubes, you use a UV map to translate the 3-dimensional surface of your model into a flat image for texture mapping.
Looks like this thread on gamedev has an example of how to extract what 3DS calls "texels" as well as materials.