Poincaré disk model: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
en>Stannic
→‎See also: commonscat
en>JRSpriggs
Line 1: Line 1:
[[Image:Procedural Texture.jpg|225px|right|thumb|A procedural floor grate texture generated with the texture editor [http://www.spiralgraphics.biz/gallery.htm Genetica].]]
Ok this may look a little crazy but we have been all excited to go to a big Memorial Day picnic  Finest Cooler 7970 yesterday with bounce houses and water slides and even a zipline for the kiddos. Usually the extra insulated models are much more high-priced, so try to obtain a cooler that is someplace in the middle of the pack. Fill the ice chest with meals that has currently been chilled in a refrigerator or freezer. Make a decision what you're looking for in the cooler prior to you open it, and hold the lid shut as substantially as possible. Stay clear of lingering over the ice chest with the lid open. The subsequent consideration is what to use for ice.<br><br><br><br>Warm meals and drinks will also accelerate the melting of your ice, so it is essential to pre-cool anything that you program to put inside the ice chest. If you are camping for a lot more than 3 days, it is a very good thought to freeze meals and perishable drinks, like milk, that you do not strategy to use until later in the tripIf you enjoyed this write-up and you would such as to receive more facts pertaining to [http://www.bestcoolerreviewshq.com/ Bestcoolerreviewshq.Com] kindly go to our web-site. I layer the pre-cooled Ice chests with Ice cubes. And other occasions use them for ICE blocks on shorter trips.<br><br>I've employed it lots, but genuinely only needed to rely on it's claim to hold ice for 5 days once. The initial day of a trip I filled it with ice and frozen meat for a significant cookout (for about 60 folks) on the 4th day of our trip. I did not open the cooler till the morning of the 4th day to make positive the meat was still cold. I returned the marine cooler and could have bought three of the Cool Max.<br><br>For this reason a massive block of strong ice, rather of hundreds of compact cubes of ice, will [http://www.Adobe.com/cfusion/search/index.cfm?term=&final+considerably&loc=en_us&siteSection=home final considerably] longer, even if the block of ice and the bag of crushed ice are the very same weight. Even with block ice, it takes a lot of it to keep an [http://www.bbc.co.uk/search/?q=ice+chest ice chest] cool for longer than 48 hours.  I use 1-gallon milk jugs for creating my own block ice. It requires 4 milk jugs to retain one particular of the 5 day” or six day” ice chests cool for three or four days, at 80ºF.<br><br>So as you can see when it comes to taking a two day camping or fishing trip this unique item would be exceptionally beneficial. The initial issue that jumps out with these new and improved ice chests is certainly the price. I won't list all the particulars, as you can come across those on every companies website, but will list the aspects I believed had been of value when deciding which to buy in the 125 Qt sized Ice chest. Chest - Given that Yeti kept popping up all over Facebook, I checked out their item 1st.
 
<!-- Missing image removed: [[Image:Cellule render1.jpg|225px|right|thumb|A procedural cellular pattern generated with [http://cellule.homeip.net Cellule].]] -->
A '''procedural texture''' is a [[computer-generated image]] created using an [[algorithm]] intended to create a realistic representation of natural elements such as [[wood]], [[marble]], [[granite]], [[metal]], [[rock (geology)|stone]], and others.
 
Usually, the natural look of the rendered result is achieved by the usage of [[fractal]] [[noise]] and [[turbulence]] [[function (mathematics)|functions]]. These functions are used as a [[numerical]] representation of the “[[randomness]]” found in nature.
 
==Solid texturing==
 
Solid texturing is a process where the texture generating function is evaluated over <math>R^3</math> at each visible surface point of the model. Traditionally these functions use [[Perlin noise]] as their basis function, but some simple functions may use more trivial methods such as the sum of sinusoidal functions for instance.
Solid textures are an alternative to the traditional 2D texture images which are applied to the surfaces of a model. It is a difficult and tedious task to get multiple 2D textures to form a consistent visual appearance on a model without it looking obviously tiled. Solid textures were created to specifically solve this problem.
 
Instead of editing images to fit a model, a function is used to evaluate the colour of the point being textured. Points are evaluated based on their 3D position, not their 2D surface position. Consequently, solid textures are unaffected by distortions of the surface parameter space, such as you might see near the poles of a sphere. Also, continuity between the surface parameterization of adjacent patches isn’t a concern either. Solid textures will remain consistent and have features of constant size regardless of distortions in the surface coordinate systems.
<ref>Ebert et al: ''Texturing and Modeling A Procedural Approach'', page 10. Morgan Kaufmann, 2003.</ref>
 
==Cellular texturing==
 
Cellular texturing differs from the majority of other procedural texture generating techniques as it does not depend on noise functions as its basis, although it is often used to complement the technique. Cellular textures are based on feature points which are scattered over a three dimensional space. These points are then used to split up the space into small, randomly tiled regions called cells. These cells often look like “lizard scales,” “pebbles,” or “flagstones”Even though these regions are discrete, the cellular basis function itself is continuous and can be evaluated anywhere in space.
<ref>Ebert et al: ''Texturing and Modeling A Procedural Approach'', page 135. Morgan Kaufmann, 2003.</ref>
 
==Genetic textures==
 
Genetic texture generation is highly experimental approach for generating textures. It is a highly automated process that uses a human to completely moderate the eventual outcome. The flow of control usually has a computer generate a set of texture candidates. From these, a user picks a selection. The computer then generates another set of textures by mutating and crossing over elements of the user selected textures.<ref>Ebert et al: ''Texturing and Modeling A Procedural Approach'', page 547. Morgan Kaufmann, 2003.</ref> For more information on exactly how this mutation and cross over generation method is achieved, see [[Genetic algorithm]]. The process continues until a suitable texture for the user is generated.
This isn't a commonly used method of generating textures as it’s very difficult to control and direct the eventual outcome. Because of this, it is typically used for experimentation or abstract textures only.
 
==Self-organizing textures==
Starting from a simple [[white noise]], [[self-organization]] processes lead to structured patterns - still with a part of randomness. [[Reaction-diffusion]] systems are a good example to generate such kind of textures.
 
==Example of a procedural marble texture==
 
(Taken from The Renderman Companion Book, by Steve Upstill)
 
<pre>
/* Copyrighted Pixar 1988 */
/* From the RenderMan Companion p.&nbsp;355 */
/* Listing 16.19  Blue marble surface shader*/
 
/*
  * blue_marble(): a marble stone texture in shades of blue
  * surface
  */
 
blue_marble(
          float  Ks    = .4,
                  Kd    = .6,
                  Ka    = .1,
                  roughness = .1,
                  txtscale = 1;
          color  specularcolor = 1)
{
    point PP;            /* scaled point in shader space */
    float csp;          /* color spline parameter */
    point Nf;            /* forward-facing normal */
    point V;            /* for specular() */
    float pixelsize, twice, scale, weight, turbulence;
 
    /* Obtain a forward-facing normal for lighting calculations. */
    Nf = faceforward( normalize(N), I);
    V = normalize(-I);
 
    /*
    * Compute "turbulence" a la [PERLIN85]. Turbulence is a sum of
    * "noise" components with a "fractal" 1/f power spectrum. It gives the
    * visual impression of turbulent fluid flow (for example, as in the
    * formation of blue_marble from molten color splines!). Use the
    * surface element area in texture space to control the number of
    * noise components so that the frequency content is appropriate
    * to the scale. This prevents aliasing of the texture.
    */
    PP = transform("shader", P) * txtscale;
    pixelsize = sqrt(area(PP));
    twice = 2 * pixelsize;
    turbulence = 0;
    for (scale = 1; scale > twice; scale /= 2)
        turbulence += scale * noise(PP/scale);
 
    /* Gradual fade out of highest-frequency component near limit */
    if (scale > pixelsize) {
        weight = (scale / pixelsize) - 1;
        weight = clamp(weight, 0, 1);
        turbulence += weight * scale * noise(PP/scale);
    }
 
    /*
    * Magnify the upper part of the turbulence range 0.75:1
    * to fill the range 0:1 and use it as the parameter of
    * a color spline through various shades of blue.
    */
    csp = clamp(4 * turbulence - 3, 0, 1);
    Ci = color spline(csp,
    color (0.25, 0.25, 0.35),      /* pale blue        */
        color (0.25, 0.25, 0.35),  /* pale blue        */
        color (0.20, 0.20, 0.30),  /* medium blue      */
        color (0.20, 0.20, 0.30),  /* medium blue      */
        color (0.20, 0.20, 0.30),  /* medium blue      */
        color (0.25, 0.25, 0.35),  /* pale blue        */
        color (0.25, 0.25, 0.35),  /* pale blue        */
        color (0.15, 0.15, 0.26),  /* medium dark blue */
        color (0.15, 0.15, 0.26),  /* medium dark blue */
        color (0.10, 0.10, 0.20),  /* dark blue        */
        color (0.10, 0.10, 0.20),  /* dark blue        */
        color (0.25, 0.25, 0.35),  /* pale blue        */
        color (0.10, 0.10, 0.20)  /* dark blue        */
        );
 
    /* Multiply this color by the diffusely reflected light. */
    Ci *= Ka*ambient() + Kd*diffuse(Nf);
 
    /* Adjust for opacity. */
    Oi = Os;
    Ci = Ci * Oi;
 
    /* Add in specular highlights. */
    Ci += specularcolor * Ks * specular(Nf,V,roughness);
}
</pre>
 
''This article was taken from [http://www.photoshoproadmap.com The Photoshop Roadmap] with written authorization''
 
==See also==
{{Portal|Computer graphics}}
*[[Texture synthesis]]
*[[Texture artist]]
*[[Procedural generation]]
*[[Perlin noise]]
*[[Self-organization]]
 
==References==
<!-- See http://en.wikipedia.org/wiki/Wikipedia:Footnotes for tips on adding references using <ref> tags -->
{{Reflist}}
 
<!-- Cellular textures: http://www.cs.brown.edu/research/vis/docs/pdf/Fleischer-1995-CTG.pdf -->
<!-- Solid and genetic textures: http://www.amazon.com/Texturing-Modeling-Procedural-Approach-Kaufmann/dp/1558608486 -->
 
==Some programs for creating textures using procedural texturing==
*[[Allegorithmic Substance Designer]]
*[[Filter Forge]]
*[[Genetica (program)|''Genetica'' (program)]] [http://www.spiralgraphics.biz/genetica.htm]
*[[DarkTree]] [http://www.darksim.com/html/dt25_description.html]
*[[Context Free Art]] [http://www.contextfreeart.org/index.html]
*[[TexRD]] [http://www.texrd.com] (based on reaction-diffusion: self-organizing textures)
*[[Texture Garden]] [http://texturegarden.com]
*[[Enhance Textures]] [http://www.shaders.co.uk]
 
[[Category:3D computer graphics]]
 
[[nl:Procedurele_generatie]]
[[de:Prozedurale Synthese]]

Revision as of 08:00, 15 February 2014

Ok this may look a little crazy but we have been all excited to go to a big Memorial Day picnic Finest Cooler 7970 yesterday with bounce houses and water slides and even a zipline for the kiddos. Usually the extra insulated models are much more high-priced, so try to obtain a cooler that is someplace in the middle of the pack. Fill the ice chest with meals that has currently been chilled in a refrigerator or freezer. Make a decision what you're looking for in the cooler prior to you open it, and hold the lid shut as substantially as possible. Stay clear of lingering over the ice chest with the lid open. The subsequent consideration is what to use for ice.



Warm meals and drinks will also accelerate the melting of your ice, so it is essential to pre-cool anything that you program to put inside the ice chest. If you are camping for a lot more than 3 days, it is a very good thought to freeze meals and perishable drinks, like milk, that you do not strategy to use until later in the trip. If you enjoyed this write-up and you would such as to receive more facts pertaining to Bestcoolerreviewshq.Com kindly go to our web-site. I layer the pre-cooled Ice chests with Ice cubes. And other occasions use them for ICE blocks on shorter trips.

I've employed it lots, but genuinely only needed to rely on it's claim to hold ice for 5 days once. The initial day of a trip I filled it with ice and frozen meat for a significant cookout (for about 60 folks) on the 4th day of our trip. I did not open the cooler till the morning of the 4th day to make positive the meat was still cold. I returned the marine cooler and could have bought three of the Cool Max.

For this reason a massive block of strong ice, rather of hundreds of compact cubes of ice, will final considerably longer, even if the block of ice and the bag of crushed ice are the very same weight. Even with block ice, it takes a lot of it to keep an ice chest cool for longer than 48 hours. I use 1-gallon milk jugs for creating my own block ice. It requires 4 milk jugs to retain one particular of the 5 day” or six day” ice chests cool for three or four days, at 80ºF.

So as you can see when it comes to taking a two day camping or fishing trip this unique item would be exceptionally beneficial. The initial issue that jumps out with these new and improved ice chests is certainly the price. I won't list all the particulars, as you can come across those on every companies website, but will list the aspects I believed had been of value when deciding which to buy in the 125 Qt sized Ice chest. Chest - Given that Yeti kept popping up all over Facebook, I checked out their item 1st.