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Erosion Effects

lynbo

By lynbo
in Effects

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Mario Marengo Newbie

Mario Marengo

Posted
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Yes all surface shader

24179[/snapback]

Nice work there Sven! :)

But how can you guys work with VOPs when things get somewhat involved like in Sven's case?

This is not at all a criticism (the shader obviously works fine and is a very nice one), I'm simply curious... I would find it almost impossible to maintain the resulting visual spaghetti (not to mention the catastrophic effects of plugging/unplugging inputs to sub-networks and in-line vops).

I know this is just a case of personal preference and really doesn't matter (unless someone else has to maintain it as well that is), but would the equivalent ~50 lines (just a guess) of clean VEX code be scarier to look at? :blink:

Sorry... having a bit of a lazy Friday and had a sudden evil urge to hijack a good thread with a pointless post :P :thumbdown:

Cheers!

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TheUsualAlex Newbie

TheUsualAlex

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This is 'hypertexture' shader, right? This is the first time I've seen someone doing this. I've only seen it in books prior. Good job, Sven. :) That's something for me to learn too!

Yeah, I guess with a full-blown, complex production shaders, I'd definitely enroute VEX coding over VOP. However, in geometry context, I'd still favor VOP for its rapid feedback. :D

Thanks!

Alex

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SvenP Newbie

SvenP

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Nice work there Sven! :)

But how can you guys work with VOPs when things get somewhat involved like in Sven's case?

This is not at all a criticism (the shader obviously works fine and is a very nice one), I'm simply curious... I would find it almost impossible to maintain the resulting visual spaghetti (not to mention the catastrophic effects of plugging/unplugging inputs to sub-networks and in-line vops).

I know this is just a case of personal preference and really doesn't matter (unless someone else has to maintain it as well that is), but would the equivalent ~50 lines (just a guess) of clean VEX code be scarier to look at?  :blink:

Sorry... having a bit of a lazy Friday and had a sudden evil urge to hijack a good thread with a pointless post :P :thumbdown:

Cheers!

24192[/snapback]

Actually i prefer to write code too and yes i am really having a lot of problems with that visual spaghetti but the people on the chan are beating me out of irc if i dont do it in vops so that they understand it ( Hey Ratman and Sum][One :D ).

And now i am of to write that shader again in code and add some more advanced stuff that i really dont want to do with vops ( another if and for in there for substepping no thanks :P ).

Sven

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Andz Newbie

Andz

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hey nice job..  I am also experimenting with the effect .. You manage to get the subtle deatiled ..

24205[/snapback]

It is just a fade from one .TGA to another. All 10 images were done with that WorldMachine.

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peliosis Newbie

peliosis

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I don't quite get what this shader does, are you going to send it to exchange to let noobs study it's full version or is it just a teaser ? :)

About shaders, if a shader is written in vex code doesit need to be compiled and installed in order to be used? Then any change would force you o recompile reinstall?

I understand code can be less messy but is it as easy to change and control it with immediate visual feedback as VOPs?

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Mario Marengo Newbie

Mario Marengo

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About shaders, if a shader is written in vex code doesit need to be compiled and installed in order to be used? Then any change would force you o recompile reinstall?

I understand code can be less messy but is it as easy to change and control it with immediate visual feedback as VOPs?

24211[/snapback]

Well, I don't want to spoil this thread so I'll just say: Yes, you need to recompile vex code (usually some tenths of a second), and you only need to reload if there's been a UI change (though even that is automatic on recooks for VOPs). But, even though I admit I'm the one guilty of having mentioned it to begin with, we should really save that discussion for a different thread.

My bad <_< sorry.

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Andz Newbie

Andz

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Posted
Nice.

Anyone who has used both WorldMachine and Terragen willing to compare and contrast?

24208[/snapback]

I see World Machine as a hightmap or mesh creator, Terragen does the same and renders it, im not sure if you can export anything else.

WorldMachine's gallery is rendered on other softwares.

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SvenP Newbie

SvenP

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Heres another version of the implicit surface shader this time code and at least for me it works better then the vops one.

Sven

#include &lt;voptype.h&gt;
#include &lt;voplib.h&gt;

float bias(float b,x;)
{
	return( pow(x,log(B)/log(0.5)));
}

float density_function(vector marchpoint,frequency,offset;
        float  roughness,attenuation,gain;
        int    turbulence;
        )
{
float density;

density = bias(gain,onoise(marchpoint*frequency-offset,turbulence,roughness,attenuation));
return(density);
}

surface Implicit(
     // Raymarching Parameters
     float maxdist = 20;
     float iso = 0.5;
     float step = 0.001;
     // density_function Parameters
     vector frequency = {1,1,1};
     vector offset = {0,0,0};
     float  roughness = 0.5;
     float  attenuation = 0.5;
     float  gain = 1;
     int    turbulence = 4;
     // shading parameters
     vector amb  = {0,0,0};
     vector diff = {0.5,0.5,0.5};
     vector spec = {1,1,1};
     float shinyness = 0.5; 
        	)
{
int front;
front = (vop_dot(I, N) &lt; 0.0) ? 1 : 0;

if ( front != 0 )
{

	vector marchpoint,marchdir,marchnormal,raydir;
	float  marchlength,density,currdist;
	marchpoint = P;
	marchdir = normalize(P-Eye);
	raydir =P+(marchdir*maxdist);
	marchlength=rayhittest(P,raydir,0.05);
	if ( marchlength &gt; 0.001 )
	{
  density=0;
  currdist=0;
  while ( density &lt; iso &amp;&amp; currdist &lt; marchlength)
  {
  	density = density_function(marchpoint,frequency,offset,roughness,attenuation,fit(gain,0,1,iso,1),turbulence);
  	currdist = distance(P,marchpoint);
  	marchpoint += marchdir*step;	
  }
  if ( density &gt;= iso)
  {
  // Shading
  	marchpoint -= marchdir*step;
  	if ( avg(marchpoint-P) &lt;= 0.01)
  	{
    marchnormal=N;
  	}
  	else
  	{
marchnormal=set(density_function(marchpoint-{0.001,0,0},frequency,offset,roughness,attenuation,fit(gain,0,1,iso,1),turbulence)-density,
  density_function(marchpoint-{0,0.001,0},frequency,offset,roughness,attenuation,fit(gain,0,1,iso,1),turbulence)-density,
  density_function(marchpoint-{0,0,0.001},frequency,offset,roughness,attenuation,fit(gain,0,1,iso,1),turbulence)-density);
  	}
  	marchnormal = frontface(marchnormal, I);
  	Cf = amb*ambient();
  	Cf += diff*diffuse(marchnormal);
  	Cf += spec*phong(normalize(marchnormal),-normalize(I),1-shinyness);
  	Of = {1,1,1};
  	Af = 1;	
  }
  else
  {
  // NoShading
  	Cf={0,0,0};
  	Of={0,0,0};
  	Af=0;
  }	
	}
	else
	{
	Cf={0,0,0};
	Of={0,0,0};
	Af=0;
	}
}
else
{
Cf = {0,0,0};
Of = {0,0,0};
Af = 0;
}
}

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