» Tutorial Effects - Mr. Wiggle
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Tutorial Effects - Mr. Wiggle

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TOC: Of Effects and Shaders
Back: Vertexshader Preparations
Next: Function Printing


Lets start with the famous MrWiggle effect, it distorts a mesh by sine waves:

The vertex shader is called for each vertex of the mesh. As you have learned here, the input of the vertex shader is the data stored in the vertex of the mesh which is now processed:

vs2ps VS(
    float4 PosO  : POSITION,
    float4 TexCd : TEXCOORD0)
{
...
}

Here we are interested in the PosO vector, which is the position of the current vertex. We will add an offset to the x coordinate of the vertex depending on its vertical position (y coordinate):

PosO.x += sin(PosO.y);

To control the waves we add some parameters:

PosO.x += sin(PosO.y * Frequency + Phase) * Amplitude;

Then the vertex shader with its inputs looks like:

float Frequency = 10;
float Phase = 0;
float Amplitude = 0.01;
 
vs2ps VS(
    float4 PosO  : POSITION,
    float4 TexCd : TEXCOORD0)
{
    //declare output struct
    vs2ps Out;
 
    //offset x coordinate
    PosO.x += sin(PosO.y * Frequency + Phase) * Amplitude;
 
    //transform position
    Out.Pos = mul(PosO, tWVP);
 
    //transform texturecoordinates
    Out.TexCd = mul(TexCd, tTex);
 
    return Out;
}

And the patch accordingly:

mr wiggle patch

Next: Function Printing
Back: Vertexshader Preparations
TOC: Of Effects and Shaders

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Shoutbox

~1h ago

mediadog: Clicking on "Missing in 64 bit builds" goes to page with warning no longer maintained, but betadocs link has no such info.

~4d ago

nanotekt: VL.stride yet again ...this time nonphotorealistic https://youtu.be/_aALr2wcj0Y ...wish evvvveryone to be well!

~9d ago

nanotekt: a brief VL.stride study https://youtu.be/B2Nlz5VZ9lM ...and a massive 'thank you' to the devvvvs!

~4d ago

everyoneishappy: @overtones this would require 4D noise, which is possible but not implemented in Fieldtrip

~12d ago

overtones: Hi! SF2D has Time & DomainOffset inputs, but SF3D only DomainOffset. Is there a way to use Time in SF3D or it makes no sense? Thx

~15d ago

joreg: @SabrinaVerhage this could be useful for you next "hacking sex" workshop: https://buttplug.io they have a .NET nuget for use in vvvv!

~23d ago

ravazquez: Happy new year!

~23d ago

sunep: Happy new year everyone!

~26d ago

ggml: confirmed. thanks

~27d ago

david: @ggml fixed. please try again.