Suggestions for lighting direction

[Ishi]

I have always wondered if there was a way or a plugin that can control where the light source on a image or layer comes from. The Curves and Levels tools are not always reliable.

 

I like to render a light source that comes from one direction such as from the left side, right side, from above or even below. The light source can be vertical, horizontal or in a tilted diagonal angle. And there should also be an option if it expands and fades as it comes closer to the center of the image. Imagine the rays of the sun of the light beam of a flashlight? I want to render that kind of lighting.

 

It would be very useful in creating an artificial light source. If there isn't a plugin written for this yet, let me be the first to make a call towards making one. Thank you.

[MikeRobe]

Interesting, there may be a way to do this with just transparent gradients, or there may be a plugin. I'll have a look around and see what I can find.

[TechnoRobbo]

You can mimic a light source by creating an empty layer on the top of the stack,

with a multiply blend mode and a white to black gradient

Use Curve to adjust lighting.

 

[Goonfella]

What about Madjik's Light Rays plugin?

http://forums.getpaint.net/index.php?showtopic=4495

Or you could try a Lens Flare?

(TR you beat me to it!)

Edited October 1, 2014 by Goonfella

[Ishi]

I am aware of making another layer and using a transparent gradient to mimic a light source. I have tried that multiple times but it has limitations. I think I might have used something like that on the shadow side of the planet of my profile picture.

 

However, it would have been better if it can be applied without needing another layer. Such a plugin would greatly affect and enhance an image that needs directional lighting to be added. I recently used the Sharpen Landscape plugin for enhancing a dull landscape image I found and it has good effects, thanks to its multiple adjustment controls. Maybe a new plugin for rendering a light source with comparable mechanics can be made.

 

 

And thanks Goonfella for linking that Light Rays Plugin. I was looking for that plugin but that's another story.

[Ego Eram Reputo]

Isn't lighting the primary function of a Normal Map?  http://en.wikipedia.org/wiki/Normal_mapping

 

There are a few plugins.  This one Normal Tools has excellent supporting documentation.

[TechnoRobbo]

do you mean something like this?

Plugin Retracted

It's under the Color menu

 

CodeLab Source Code

Hidden Content:

// Submenu: Color
// Name: TR's SimpleLight
// Title: TR's SimpleLight- v1.0
// Author: TechnoRobbo
// URL: http://www.technorobbo.com

#region UICode
Pair<double, double> Amount1 = Pair.Create( 0.0 , 0.0 ); // Hot Spot
double Amount2 = 0.5; // [0,4] Coverage
byte Amount3 = 0; // [1] Type|Normal|Flood|Spot
double Amount4 = 1; // [0.5,2] Gain
#endregion

void Render(Surface dst, Surface src, Rectangle rect)
{
    // Delete any of these lines you don't need
    Rectangle selection = EnvironmentParameters.GetSelection(src.Bounds).GetBoundsInt();
    int CenterX = ((selection.Right - selection.Left) / 2)+selection.Left;
    int CenterY = ((selection.Bottom - selection.Top) / 2)+selection.Top;
    ColorBgra PrimaryColor = (ColorBgra)EnvironmentParameters.PrimaryColor;
    ColorBgra SecondaryColor = (ColorBgra)EnvironmentParameters.SecondaryColor;
    int BrushWidth = (int)EnvironmentParameters.BrushWidth;
    
    System.Drawing.PointF org =new System.Drawing.PointF( (float)Amount1.First, (float)Amount1.Second);
    
    
    float range =  (float)Amount2;
    
    ColorBgra CP;
    for (int y = rect.Top; y < rect.Bottom; y++)
    {
        if (IsCancelRequested) return;
        for (int x = rect.Left; x < rect.Right; x++)
        {
            float relx = (float)(x -  CenterX) / (float)CenterX;   
            float rely = (float)(y -  CenterY) / (float)CenterY;    
            float dist =(float) Math.Sqrt((org.X - relx )*(org.X - relx )
                    + (org.Y - rely)*(org.Y - rely));   
            float coeff = (dist > range)? 0: (1f - dist/range);    
            
            coeff *= (float)Amount4;
            
            
            if (Amount3==1)
            {
                coeff = (float)Math.Sqrt(coeff);
            }else if (Amount3==2)
            {
                coeff *= coeff;
            }
                
            CP = src[x,y];
            float tmp = (float)CP.R * coeff; 
            tmp = (tmp > 255) ? 255: tmp;
            CP .R = (byte)tmp;
            
            tmp = (float)CP.G * coeff;  
            tmp = (tmp>255) ? 255: tmp;
            CP .G = (byte)tmp;
            
            tmp = (float)CP.B * coeff;     
            tmp = (tmp>255) ? 255: tmp;
            CP .B = (byte)tmp;
            
            CP.A = (byte)CP.A;
            dst[x,y] = CP;
        }
    }
}

 

not published yet - need to make it 3.5 and Plugin browser compatible.

[Ishi]

Not 3.5 compatible? That's why it didn't appear on mine...

[TechnoRobbo]

It won't take me too long to port it to 3.5

[TechnoRobbo]

PDN 3.5 compatible version available.

http://forums.getpaint.net/index.php?/topic/30146-trs-simple-light/?p=417409

[Ishi]

That's for that TechnoRobbo. I'm testing it now.       Gotta find more images to test this with. Thanks again..

 

It deserves to be popularized....

[TechnoRobbo]

Sorry,it turns out that Boltbait had written a similar plugin with more options

 

http://forums.getpaint.net/index.php?/topic/28500-

[Ishi]

That's OK. There are differences to between their functions.