Hello,
Are there resources/tutorials that anyone can recommend for implementing a spot light in our framework? (One of the project requirements: phong shader/light node class combination.)
Thank you,
Jack
Etwas konkreter noch! Wie bekommt man eine Berechnung heraus, zum Beispiel durch console.log, die Shader passiert? Wir haben zB
//spot ... compute angle between spot light direction and light vector
float angle = dot(u_light2Direction,-lightVec);
... Und wissen noch nicht ob wir da überhaupt einen guten Wert bekommen.
//spot ... compute angle between spot light direction and light vector
float angle = dot(u_light2Direction,-lightVec);
... Und wissen noch nicht ob wir da überhaupt einen guten Wert bekommen.
Hi!
As far as I'm aware, there is no direct way to get output from your shader code to your console (remember that GLSL code is running several thousand times a second in parallel on your GPU, there's no way you could evaluate the amount of output that would generate), however, you can "cheat" a little by putting the information you want to output into the color the shader puts out.
There's two ways of doing this, one is making a condition that you want to check (say angle < 0.5) and then, if that condition is true, just set gl_fragment_color to an easily recognizble value (vec4(1, 0, 0, 1) = bright red for example). This can show you, where on your screen a certain condition holds.
The other way is just outputting variables directly into your color (by e.g. using gl_fragment_color = vexc4(angle, 0, 0, 1)) and using a screen-capture tool in combination with any painting tool or color-picker to read the exact values of variables from your screen.
These can really help with debugging GLSL code, even if they may seem a bit convoluted. ;)
Hope that helps a bit!
LG,
Jonathan
As far as I'm aware, there is no direct way to get output from your shader code to your console (remember that GLSL code is running several thousand times a second in parallel on your GPU, there's no way you could evaluate the amount of output that would generate), however, you can "cheat" a little by putting the information you want to output into the color the shader puts out.
There's two ways of doing this, one is making a condition that you want to check (say angle < 0.5) and then, if that condition is true, just set gl_fragment_color to an easily recognizble value (vec4(1, 0, 0, 1) = bright red for example). This can show you, where on your screen a certain condition holds.
The other way is just outputting variables directly into your color (by e.g. using gl_fragment_color = vexc4(angle, 0, 0, 1)) and using a screen-capture tool in combination with any painting tool or color-picker to read the exact values of variables from your screen.
These can really help with debugging GLSL code, even if they may seem a bit convoluted. ;)
Hope that helps a bit!
LG,
Jonathan
Great tip Jonathan!
I can also recommend these resources (in general, not only for spotlights):
I can also recommend these resources (in general, not only for spotlights):
- https://learnopengl.com/Lighting/Light-casters also on the slides
- https://webglfundamentals.org/webgl/lessons/webgl-3d-lighting-spot.html
Best regards,
Klaus Eckelt