Hot answers tagged uvw-mapping
16
Your understanding is close. Each 3D model is made out of vertexes. Each vertex usually defines the location of a point in space, a normal (used in lighting calculations) and 1 or more texture coordinates. These are generally designated as u for the horizontal part of the texture and v for the vertical.
When an object is textured, these coordinates are used ...
15
It sounds like you want to keep the speed of the object at some constant value over the entire curve - knowing the arc-length won't help you do this. It will help you calculate at what time the object would reach its end-point if it were going at that speed, so it will be better than what you have now (the object will have the same average speed between all ...
11
This is the way I understand it. Could be totally wrong, but I'm sure someone will flame correct me if I'm wrong.
The mathematical theory behind UVW texture mapping is similar to the theory behind UV texture mapping.
See Bummzack's link here: What exactly is UV and UVW Mapping? to get a better explanation of what UV mapping is. Basically, you're mapping ...
8
With full source (or even just a thorough explanation) of a perspective correct textured triangle rasterizer being too long for an answer, I'll gladly refer you to Chris Hecker's classic series of articles on the topic, including source:
http://chrishecker.com/Miscellaneous_Technical_Articles
From your link I assume you are using Flash as a platform, so I ...
7
I think you are right. You would
really like to tile your bricks,
because it saves a lot of memory
space and is also quick in your GPU.
Baking the lighting does need a
unique texturing, because no place
is the same. You could tile some
parts of your texture, for example,
on really straight long places. (I'm
no UV wrapper, but I do think that
is possible to ...
4
Consider a triangle.
Each corner has a UV coordinate. You interpolate between these to get a set of UV coordinates for each pixel. (There's also perspective in play here but let's ignore that for the moment).
Then, you fetch a texel from the texture from the coordinates U and V. Which is to say, a pixel from the texture coordinate x,y - same thing, ...
2
I'm almost sure this is because you're using TextureAddressMode.Mirror instead of TextureAddressMode.Wrap.
Change the value in the sampler state before rendering the primitives. I think it should be something like:
GraphicsDevice.SamplerStates[0].AddressU = TextureAddressMode.Wrap;
GraphicsDevice.SamplerStates[0].AddressV = TextureAddressMode.Wrap;
1
You can add to your vertex these arrays:
int[4] TextureId;
float[4] TextureWeight;
and in your shader you can do the blend,
finalTexColor = tex0sample * TextureWeight[0] + tex1sample * TextureWeight[1] +tex2sample * TextureWeight[2] + tex3sample * TextureWeight[3]
you can see this article to know how.
1
There is no easy solution to your problem. In common 3D graphics surfaces are composed out of triangles for a reasons (easy to use, always planar, etc..). Even when you order to draw quads GPU renders them as pairs of triangles.
Your problem comes from the fact, that it is impossible to properly split quad into triangles when they are not planar and/or ...
1
You're going to have to recreate your shape as a 3D mesh and run it through a software renderer to get any decent output that isn't a single-purpose hack like the texture matrix solution. If you attempt this in 2D you don't have enough information, like you've noticed.
Let me introduce you to a great article on perspective texture mapping in software:
...
1
Depends on what you are trying to achieve, you could define your figure in 3D space to make the distortion as suggested in the link.
If it's not 3D you are looking for then an applicable hack is to use a polygon "net", split the figure into a suitable number of small squares and you can do the transformation as you see fit. For some simple transformations ...
1
I'm not sure I understand your diagram. Are you saying you want the image to repeat along the edge of the disk (i.e. the lines represent the borders of the image?) If so, that may produce visual artifacts that you might want to consider first.
The way you've drawn it here, the image will compress near the inner part of the disk, and stretch near the outer ...
Only top voted, non community-wiki answers of a minimum length are eligible