Hi,
you are outputting the position as color, that's why you see black (because
these have negative coordinate values) and the three values. Just set an
arbitrary fixed color value in the frag-shader to see anything. But if you need
to see colors, then you need to define your own vertex
Actually I solved it... one of the problems was that the number I was using for
the attribute was too big (or reserved).
I am forced to use OpenGL ES 2.0 because I develop on iOS platform!
Thank you anyway for your advice.
Cheers,
John
This is the working code
Code:
#define
I want to add that this is the fragment shader I used for drawing the wireframe
model
Code:
precision highp float;
varying vec3 vBC;
#extension GL_OES_standard_derivatives : enable
float edgeFactor(){
vec3 d = fwidth(vBC);
vec3 a3 = smoothstep(vec3(0.0), d*1.0, vBC);
return
Hi,
for learning basic shader programming you do not have to constrain yourself to
opengl es 2.0. It is sufficient to do the same basic stuff with OGL 3.0 in
order at least to understand the difference between assigning a coordinate
value and a color value as the final fragment value. I
I found a solution which involves computing the barycentric coordinates.
However it seems that is not working properly.
To compute the barycentric coordinates I need to associate to the vertices of
the triangles a coordinate among
(1,0,0) (0,1,0) (0,0,1)
for doing that I use the following
Hi,
I am using OpenSceneGraph on iOS, using OpenGL ES 2.0.
I am having hard time to figure out how to draw polygon lines using shaders.
I'd like to draw a simple box with lines. However I can't find a way because
osg::PolygonMode::LINE does not work.
In fact
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