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This article mainly introduces OpenGL Shader how to achieve a simple transition effect, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.

Gradual transition

The mix function is used to mix two texture images, and time is used to control the intensity of the texture mixing of the second image to achieve the gradient effect.

# define time iTimevoid main () {vec2 uv = gl_FragCoord.xy / iResolution.xy; vec4 texture1 = texture (iChannel1,uv); vec4 texture2 = texture (iChannel2,uv); float progress = abs (sin (time)); gl_FragColor = mix (texture1,texture2,progress);} switch transition

Switching animation and gradient animation also use the mix function to achieve the effect. At the same time, combined with the step function to determine whether the current texture value is greater than uv.x to control whether the current texture is the first or the second, so as to achieve the texture shutter displacement effect. Here is a combination of mix and step functions to achieve animation, the same use of if-else can also achieve the same purpose, but it has been mentioned before that in glsl it is best to give priority to the use of built-in functions to achieve the effect, reducing the use of if-else judgment statements.

X-axis switch # define time iTimevoid main () {vec2 uv = gl_FragCoord.xy / iResolution.xy; vec4 texture1 = texture (iChannel1,uv); vec4 texture2 = texture (iChannel2,uv); float progress = abs (sin (time)); gl_FragColor = mix (texture1,texture2,step (uv.x,progress));}

Y-axis switch # define time iTimevoid main () {vec2 uv = gl_FragCoord.xy / iResolution.xy; vec4 texture1 = texture (iChannel1,uv); vec4 texture2 = texture (iChannel2,uv); float progress = abs (sin (time)); gl_FragColor = mix (texture1,texture2,step (uv.y,progress));}

Diagonal switching

Diagonal switching is also a combination of mix and step functions, making use of the diagonal alignment characteristic of x-y=0, when the values reach 0, it switches to the second texture image.

# define time iTimevoid main () {vec2 uv = gl_FragCoord.xy / iResolution.xy; vec4 texture1 = texture (iChannel1,uv); vec4 texture2 = texture (iChannel2,uv); float progress = sin (time); gl_FragColor = mix (uv.x-uv.y,-progress);}

Displacement transition

The transition effect is realized by holding the position of the bottom texture and covering the upper texture. The displacement transition is that the two texture objects do not overlap, such as the effect similar to the rotation map, and the effect is to move in the same direction at the same time. The displacement animation offsets the overall texture and allocates the proportion of the first texture and the second texture through the value of progress.

X-axis displacement # define time iTimevoid main () {vec2 uv = gl_FragCoord.xy / iResolution.xy; vec2 newUv = uv; float progress = abs (sin (time)); vec4 texture3; newUv.x-= progress; if (uv.x > = progress) {texture3 = texture (iChannel1,newUv);} else {texture3 = texture (iChannel2,newUv);} gl_FragColor = texture3;}

Y-axis displacement # define time iTimevoid main () {vec2 uv = gl_FragCoord.xy / iResolution.xy; vec2 newUv = uv; float progress = abs (sin (time)); vec4 texture3; newUv.y-= progress; if (uv.y > = progress) {texture3 = texture (iChannel1,newUv);} else {texture3 = texture (iChannel2,newUv);} gl_FragColor = texture3;}

Thank you for reading this article carefully. I hope the article "how to achieve the simple transition effect of OpenGL Shader" shared by the editor will be helpful to everyone. At the same time, I also hope that you will support us and pay attention to the industry information channel. More related knowledge is waiting for you to learn!

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