[osg-users] How to generate fixed alpha value?

[Julien Valentin]

Hi Judy
there's no such thins as pseudo-random generator in glsl itself but you can code it for ex:Linear Congruent Generators : https://math.stackexchange.com/questions/337782/pseudo-random-number-generation-on-the-gpu
I haven't tested so give us experience feedbacks about this func

(Personnally I generally export random values collected in a image with CPU rand() func into a texture and sample it in the shader with gl_Instance_id )

Cheers


xdfanfan wrote:
> Hi all,
> Now，I have a flt. model with itself texture，but the internal format of the texture is RGB，not with ALPHA value，so the ALPHA TEST function is disabled.
> My question is how to generate some random fixed alpha value of the texture with the GLSL language，So that I can use the ALPHA TEST function to fufill the point cloud.
> 
> 
> Thanks very much!
> Judy
> 
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