bricksphd

A shader program that changes with tmie. 
This shader program builds on our previous shader, https://shaderfrog.com/app/view/3154.
In this shader, we change the position of the light with time, but entirely on the GPU. This begins to open up some exciting possibilities for us on the GPU.

Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


Introduction to Dynamic Shaders

A shader program that renders an object with simple diffuse lighting. 
This shader program builds on our previous shader, https://shaderfrog.com/app/view/3151.
To get this shader, we reintroduce the external color variable.
We also add a directionToLight variable, which points to the light source.
To calculate the diffuse lighting on this object, we calculate the dot product of the normal of the surface and the direction to the light. This gives the cosine of the angle between the surface the light source, effectively giving us the amount of the light the reaches the surface. We call this diffuse lighting.
Although this lighting is simple to calculate, it has several problems.
First, it does not calculate shadows.
Second, it does not calculate ambient lighting or diffuse bleeding.
Third, it assumes the light source is infinitely far away (which is not a bad assumption for lighting from the sun, but fails under must other cases).
Clearly, this is a biased form of rendering.

Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


Diffuse Lighting

A minimal shader demonstrating the roles of the vertex shader and the fragment shader in a shader program. Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd

Unilluminated Shader

A shader program that introduces uvs. 
This shader program builds on our previous shader, https://shaderfrog.com/app/view/3155.
In this shader, we introduce uvs. UVs can be used to map textures to an object, or for more advances fragment shaders. In this fragment shader we simply superimpose the uv coordinates on our surface.

Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


Shader with UVs

A shader program that uses uvs to make distort vertices on an object and adds color using the same technique. 
This shader program builds on our previous shader, https://shaderfrog.com/app/view/3219.
In this shader, we use uvs to move individual vertices differently. In this case, we use uvs and a triginometric function to alter vertices.

Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


Christmas Ornament

A shader program that uses uvs to make distort vertices on an object. 
This shader program builds on our previous shader, https://shaderfrog.com/app/view/3159.
In this shader, we use uvs to move individual vertices differently. In this case, we use uvs and a triginometric function to alter vertices.

Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


Spiked Vertex Shader

A shader program that uses uvs to make a crazy checkerboard pattern. 
This shader program builds on our previous shader, https://shaderfrog.com/app/view/3156.
In this shader, we use uvs to add a checkerboard pattern to our surfaces.

Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


Checkerboard UVs

A shader program that renders an object with simple diffuse and ambient lighting. 
This shader program builds on our previous shader, https://shaderfrog.com/app/view/3152.
Since a purely diffuse shader program does not handle ambient lighting, one way is to add an ambient bias to the fragment shader. This adds additional bias to the render, but can make the result more visually appealing. Note that large amounts of ambient lighting are almost universally visually distracting.

Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


Diffuse + Ambient Lighting

A shader program that uses uvs to make distort UVs on an object. 
This shader program builds on our previous shader, https://shaderfrog.com/app/view/3157.
In this shader, we use uvs to move individual vertices differently. In this case, we use uvs and a triginometric function to alter vertices.

Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


Distorted UV Shader

A shader program that modifies vertices. 
This shader program builds on our previous shader, https://shaderfrog.com/app/view/3155.
The GPU can dynamically move vertices as well as coloring pixels. This allows for dynamically created terrain, flowing water, realistic cloth, and a host of other realtime effects.
In this shader, the model is being moved, but only on the GPU. Notice how the combination of the dynamic lighting and the dynamic movement creates an interesting effect.

Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


Moving vertices

A shader program that renders an object with local lights (as opposed to lights that are infinitely far away). 
This shader program builds on our previous shader, https://shaderfrog.com/app/view/3153.
In this shader, we change our light from being defined as a direction to a position in world space.
To calculate the direction from a point to this light, we need to track our position in world space for each fragment as well.
Then in our fragment shader, we calculate the direction to the light by subtracting the world position from the light position. It is very important to normalize this result. If you take out the normalize() call, the strength of the light will be multiplied by the distance to the light.

Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


World Space Lighting

An unlit shader program that renders the normals of an object in rgb. 
This shader program introduces several new concepts over our previous shader, https://shaderfrog.com/app/view/3150.
First, we request addition information from the GPU to use in the vertex shader, the modelMatrix and the normal. 
Second, we declare a variable, vNormal, that we will use to store custom information that will be passed from our vertex shader to the fragment shader.
Third, we perform an additional calculation in our vertex shader, namely, we multiply the normal (which is in model space) by the model to world space matrix to get the normal in world space. To do this, notice several things. First, we add a w component to the three dimensional normal, but we force that w to be 0. This effectively removes the translation effects of the model to world space transformation. This is what we want since normals are vectors and don't have a sense of position. Second, we normalize the result, we assures us that the result is of length one. This will important later when we calculate lighting with these normals. Third, we call ".xyz" at the end of the line to get the xyz values of the result as a vec3. You can call the components of a vector in any order, for example ".zyx" This is called swizzling and can be very useful.
Lastly, we use this as the color for our fragment shader. 
Note that this can be a useful shader for debugging the normals of a model you have created when something isn't rendering right. You can find a similar shader for Unity here: https://github.com/bricksSeeds/unity/tree/master/DebuggingShaders


Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


Normal Shader

A minimal shader with an external variable (uniform). Created for Computer Graphics 4620, a course offered at the University of Nebraska at Omaha. @bricksphd


bricksphd's Shaders (13)