How to interpret output position values of Geometry node
$begingroup$
I have a simple sphere with a material. And I want to know how understand information the Geometry node gives. I printed this information through OSL shader. Can somebody please explain to me why the position output is roughly (10 10 10), while the object world location is (0 0 30)?
shader Inspector(float input=0,output color debug=0)
{
debug = input;
printf("n");
printf("%f" , debug );
}
nodes osl
asked 5 hours ago
Oleksiy Plotnyts'kyyOleksiy Plotnyts'kyy
355
$endgroup$
add a comment |
$begingroup$
I have a simple sphere with a material. And I want to know how understand information the Geometry node gives. I printed this information through OSL shader. Can somebody please explain to me why the position output is roughly (10 10 10), while the object world location is (0 0 30)?
shader Inspector(float input=0,output color debug=0)
{
debug = input;
printf("n");
printf("%f" , debug );
}
nodes osl
asked 5 hours ago
Oleksiy Plotnyts'kyyOleksiy Plotnyts'kyy
355
$endgroup$
$begingroup$
How big is your sphere? Is the sphere's origin at its center? Where's the file that shows that problem? Which version of blender are you using? Gosh, so many questions... This is because the Position gives exactly the world coordinates of the point being sampled.
$endgroup$
– Secrop
3 hours ago
add a comment |
$begingroup$
I have a simple sphere with a material. And I want to know how understand information the Geometry node gives. I printed this information through OSL shader. Can somebody please explain to me why the position output is roughly (10 10 10), while the object world location is (0 0 30)?
shader Inspector(float input=0,output color debug=0)
{
debug = input;
printf("n");
printf("%f" , debug );
}
nodes osl
asked 5 hours ago
Oleksiy Plotnyts'kyyOleksiy Plotnyts'kyy
355
$endgroup$
I have a simple sphere with a material. And I want to know how understand information the Geometry node gives. I printed this information through OSL shader. Can somebody please explain to me why the position output is roughly (10 10 10), while the object world location is (0 0 30)?
shader Inspector(float input=0,output color debug=0)
{
debug = input;
printf("n");
printf("%f" , debug );
}
nodes osl
nodes osl
asked 5 hours ago
Oleksiy Plotnyts'kyyOleksiy Plotnyts'kyy
355
asked 5 hours ago
Oleksiy Plotnyts'kyyOleksiy Plotnyts'kyy
355
edited 4 hours ago
Oleksiy Plotnyts'kyy
asked 5 hours ago
Oleksiy Plotnyts'kyyOleksiy Plotnyts'kyy
355
asked 5 hours ago
Oleksiy Plotnyts'kyyOleksiy Plotnyts'kyy
355
asked 5 hours ago
Oleksiy Plotnyts'kyyOleksiy Plotnyts'kyy
355
355
$begingroup$
How big is your sphere? Is the sphere's origin at its center? Where's the file that shows that problem? Which version of blender are you using? Gosh, so many questions... This is because the Position gives exactly the world coordinates of the point being sampled.
$endgroup$
– Secrop
3 hours ago
add a comment |
$begingroup$
How big is your sphere? Is the sphere's origin at its center? Where's the file that shows that problem? Which version of blender are you using? Gosh, so many questions... This is because the Position gives exactly the world coordinates of the point being sampled.
$endgroup$
– Secrop
3 hours ago
$begingroup$
How big is your sphere? Is the sphere's origin at its center? Where's the file that shows that problem? Which version of blender are you using? Gosh, so many questions... This is because the Position gives exactly the world coordinates of the point being sampled.
$endgroup$
– Secrop
3 hours ago
$begingroup$
How big is your sphere? Is the sphere's origin at its center? Where's the file that shows that problem? Which version of blender are you using? Gosh, so many questions... This is because the Position gives exactly the world coordinates of the point being sampled.
$endgroup$
– Secrop
3 hours ago
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
The Position output of the geometry node yields the current shading point (on the surface of your sphere) in World Space. It is the equivalent of the global variable P in OSL.
A lot of the outputs are equvalent to OSL Globals:
Position: point P Position of the point you are shading.
Incoming: The negative of OSL's vector I: The incident ray direction, pointing from the viewing position to the shading position P.
Normal: normal N The surface “Shading” normal of the surface at P.
True Normal: normal Ng The true surface normal at P.(before bump mapping, etc.)
Parametric: float u, v The 2D parametric coordinates of P, as defined for the current object.
The rest as per manual
Your interpretation of point as float seems to have unpredictable results..
I've found you have to use the printed variable in some way to prevent the print from being optimized? away.
shader Inspector(
point input = 0.0,
output color debug = 0.0
)
{
debug = input;
//pointless calculation to prevent printf being optimized away
debug[0] = pow(debug[0],1);
printf("%f n",debug);
}
answered 3 hours ago
Robin BettsRobin Betts
7,0771628
$endgroup$
$begingroup$
Thank you. It seems to be working with vector type as well if we add a pointless calculation. I'm wondering why there is no such optimization with float interpretation.
$endgroup$
– Oleksiy Plotnyts'kyy
2 hours ago
1
$begingroup$
@OleksiyPlotnyts'kyy maybe because, as Secrop points out, the cast frompointtofloatinvolves a calculation.. the cast between triples just involves passing the components on, unaltered.
$endgroup$
– Robin Betts
2 hours ago
add a comment |
$begingroup$
You're turning a vector into a float. So float=(v[0]+v[1]+v[2])/3.
this will give the correct result:
shader Inspector(float xcomp=0, float ycomp=0, float zcomp=0, output color debug=0)
{
debug = (xcomp+ycomp+zcomp)/3;
printf("n");
printf("%f,%f,%f >> %f" , xcomp, ycomp, zcomp, debug);
}
Use the SeparateXYZ and connect each components to the script.
answered 3 hours ago
SecropSecrop
1,893614
$endgroup$
$begingroup$
It doesn't give any output with vector type now.
$endgroup$
– Oleksiy Plotnyts'kyy
3 hours ago
$begingroup$
Ahh.. so that's what the cast frompointtofloatis doing..I couldn't work it out...
$endgroup$
– Robin Betts
2 hours ago
2
$begingroup$
@OleksiyPlotnyts'kyy, ohh, osl optimizations.. I'm changing the script ;)
$endgroup$
– Secrop
2 hours ago
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
The Position output of the geometry node yields the current shading point (on the surface of your sphere) in World Space. It is the equivalent of the global variable P in OSL.
A lot of the outputs are equvalent to OSL Globals:
Position: point P Position of the point you are shading.
Incoming: The negative of OSL's vector I: The incident ray direction, pointing from the viewing position to the shading position P.
Normal: normal N The surface “Shading” normal of the surface at P.
True Normal: normal Ng The true surface normal at P.(before bump mapping, etc.)
Parametric: float u, v The 2D parametric coordinates of P, as defined for the current object.
The rest as per manual
Your interpretation of point as float seems to have unpredictable results..
I've found you have to use the printed variable in some way to prevent the print from being optimized? away.
shader Inspector(
point input = 0.0,
output color debug = 0.0
)
{
debug = input;
//pointless calculation to prevent printf being optimized away
debug[0] = pow(debug[0],1);
printf("%f n",debug);
}
answered 3 hours ago
Robin BettsRobin Betts
7,0771628
$endgroup$
$begingroup$
Thank you. It seems to be working with vector type as well if we add a pointless calculation. I'm wondering why there is no such optimization with float interpretation.
$endgroup$
– Oleksiy Plotnyts'kyy
2 hours ago
1
$begingroup$
@OleksiyPlotnyts'kyy maybe because, as Secrop points out, the cast frompointtofloatinvolves a calculation.. the cast between triples just involves passing the components on, unaltered.
$endgroup$
– Robin Betts
2 hours ago
add a comment |
$begingroup$
The Position output of the geometry node yields the current shading point (on the surface of your sphere) in World Space. It is the equivalent of the global variable P in OSL.
A lot of the outputs are equvalent to OSL Globals:
Position: point P Position of the point you are shading.
Incoming: The negative of OSL's vector I: The incident ray direction, pointing from the viewing position to the shading position P.
Normal: normal N The surface “Shading” normal of the surface at P.
True Normal: normal Ng The true surface normal at P.(before bump mapping, etc.)
Parametric: float u, v The 2D parametric coordinates of P, as defined for the current object.
The rest as per manual
Your interpretation of point as float seems to have unpredictable results..
I've found you have to use the printed variable in some way to prevent the print from being optimized? away.
shader Inspector(
point input = 0.0,
output color debug = 0.0
)
{
debug = input;
//pointless calculation to prevent printf being optimized away
debug[0] = pow(debug[0],1);
printf("%f n",debug);
}
answered 3 hours ago
Robin BettsRobin Betts
7,0771628
$endgroup$
$begingroup$
Thank you. It seems to be working with vector type as well if we add a pointless calculation. I'm wondering why there is no such optimization with float interpretation.
$endgroup$
– Oleksiy Plotnyts'kyy
2 hours ago
1
$begingroup$
@OleksiyPlotnyts'kyy maybe because, as Secrop points out, the cast frompointtofloatinvolves a calculation.. the cast between triples just involves passing the components on, unaltered.
$endgroup$
– Robin Betts
2 hours ago
add a comment |
$begingroup$
The Position output of the geometry node yields the current shading point (on the surface of your sphere) in World Space. It is the equivalent of the global variable P in OSL.
A lot of the outputs are equvalent to OSL Globals:
Position: point P Position of the point you are shading.
Incoming: The negative of OSL's vector I: The incident ray direction, pointing from the viewing position to the shading position P.
Normal: normal N The surface “Shading” normal of the surface at P.
True Normal: normal Ng The true surface normal at P.(before bump mapping, etc.)
Parametric: float u, v The 2D parametric coordinates of P, as defined for the current object.
The rest as per manual
Your interpretation of point as float seems to have unpredictable results..
I've found you have to use the printed variable in some way to prevent the print from being optimized? away.
shader Inspector(
point input = 0.0,
output color debug = 0.0
)
{
debug = input;
//pointless calculation to prevent printf being optimized away
debug[0] = pow(debug[0],1);
printf("%f n",debug);
}
answered 3 hours ago
Robin BettsRobin Betts
7,0771628
$endgroup$
The Position output of the geometry node yields the current shading point (on the surface of your sphere) in World Space. It is the equivalent of the global variable P in OSL.
A lot of the outputs are equvalent to OSL Globals:
Position: point P Position of the point you are shading.
Incoming: The negative of OSL's vector I: The incident ray direction, pointing from the viewing position to the shading position P.
Normal: normal N The surface “Shading” normal of the surface at P.
True Normal: normal Ng The true surface normal at P.(before bump mapping, etc.)
Parametric: float u, v The 2D parametric coordinates of P, as defined for the current object.
The rest as per manual
Your interpretation of point as float seems to have unpredictable results..
I've found you have to use the printed variable in some way to prevent the print from being optimized? away.
shader Inspector(
point input = 0.0,
output color debug = 0.0
)
{
debug = input;
//pointless calculation to prevent printf being optimized away
debug[0] = pow(debug[0],1);
printf("%f n",debug);
}
answered 3 hours ago
Robin BettsRobin Betts
7,0771628
answered 3 hours ago
Robin BettsRobin Betts
7,0771628
answered 3 hours ago
Robin BettsRobin Betts
7,0771628
answered 3 hours ago
Robin BettsRobin Betts
7,0771628
7,0771628
$begingroup$
Thank you. It seems to be working with vector type as well if we add a pointless calculation. I'm wondering why there is no such optimization with float interpretation.
$endgroup$
– Oleksiy Plotnyts'kyy
2 hours ago
1
$begingroup$
@OleksiyPlotnyts'kyy maybe because, as Secrop points out, the cast frompointtofloatinvolves a calculation.. the cast between triples just involves passing the components on, unaltered.
$endgroup$
– Robin Betts
2 hours ago
add a comment |
$begingroup$
Thank you. It seems to be working with vector type as well if we add a pointless calculation. I'm wondering why there is no such optimization with float interpretation.
$endgroup$
– Oleksiy Plotnyts'kyy
2 hours ago
1
$begingroup$
@OleksiyPlotnyts'kyy maybe because, as Secrop points out, the cast frompointtofloatinvolves a calculation.. the cast between triples just involves passing the components on, unaltered.
$endgroup$
– Robin Betts
2 hours ago
$begingroup$
Thank you. It seems to be working with vector type as well if we add a pointless calculation. I'm wondering why there is no such optimization with float interpretation.
$endgroup$
– Oleksiy Plotnyts'kyy
2 hours ago
$begingroup$
Thank you. It seems to be working with vector type as well if we add a pointless calculation. I'm wondering why there is no such optimization with float interpretation.
$endgroup$
– Oleksiy Plotnyts'kyy
2 hours ago
1
1
$begingroup$
@OleksiyPlotnyts'kyy maybe because, as Secrop points out, the cast from
point to float involves a calculation.. the cast between triples just involves passing the components on, unaltered.$endgroup$
– Robin Betts
2 hours ago
$begingroup$
@OleksiyPlotnyts'kyy maybe because, as Secrop points out, the cast from
point to float involves a calculation.. the cast between triples just involves passing the components on, unaltered.$endgroup$
– Robin Betts
2 hours ago
add a comment |
$begingroup$
You're turning a vector into a float. So float=(v[0]+v[1]+v[2])/3.
this will give the correct result:
shader Inspector(float xcomp=0, float ycomp=0, float zcomp=0, output color debug=0)
{
debug = (xcomp+ycomp+zcomp)/3;
printf("n");
printf("%f,%f,%f >> %f" , xcomp, ycomp, zcomp, debug);
}
Use the SeparateXYZ and connect each components to the script.
answered 3 hours ago
SecropSecrop
1,893614
$endgroup$
$begingroup$
It doesn't give any output with vector type now.
$endgroup$
– Oleksiy Plotnyts'kyy
3 hours ago
$begingroup$
Ahh.. so that's what the cast frompointtofloatis doing..I couldn't work it out...
$endgroup$
– Robin Betts
2 hours ago
2
$begingroup$
@OleksiyPlotnyts'kyy, ohh, osl optimizations.. I'm changing the script ;)
$endgroup$
– Secrop
2 hours ago
add a comment |
$begingroup$
You're turning a vector into a float. So float=(v[0]+v[1]+v[2])/3.
this will give the correct result:
shader Inspector(float xcomp=0, float ycomp=0, float zcomp=0, output color debug=0)
{
debug = (xcomp+ycomp+zcomp)/3;
printf("n");
printf("%f,%f,%f >> %f" , xcomp, ycomp, zcomp, debug);
}
Use the SeparateXYZ and connect each components to the script.
answered 3 hours ago
SecropSecrop
1,893614
$endgroup$
$begingroup$
It doesn't give any output with vector type now.
$endgroup$
– Oleksiy Plotnyts'kyy
3 hours ago
$begingroup$
Ahh.. so that's what the cast frompointtofloatis doing..I couldn't work it out...
$endgroup$
– Robin Betts
2 hours ago
2
$begingroup$
@OleksiyPlotnyts'kyy, ohh, osl optimizations.. I'm changing the script ;)
$endgroup$
– Secrop
2 hours ago
add a comment |
$begingroup$
You're turning a vector into a float. So float=(v[0]+v[1]+v[2])/3.
this will give the correct result:
shader Inspector(float xcomp=0, float ycomp=0, float zcomp=0, output color debug=0)
{
debug = (xcomp+ycomp+zcomp)/3;
printf("n");
printf("%f,%f,%f >> %f" , xcomp, ycomp, zcomp, debug);
}
Use the SeparateXYZ and connect each components to the script.
answered 3 hours ago
SecropSecrop
1,893614
$endgroup$
You're turning a vector into a float. So float=(v[0]+v[1]+v[2])/3.
this will give the correct result:
shader Inspector(float xcomp=0, float ycomp=0, float zcomp=0, output color debug=0)
{
debug = (xcomp+ycomp+zcomp)/3;
printf("n");
printf("%f,%f,%f >> %f" , xcomp, ycomp, zcomp, debug);
}
Use the SeparateXYZ and connect each components to the script.
answered 3 hours ago
SecropSecrop
1,893614
edited 2 hours ago
answered 3 hours ago
SecropSecrop
1,893614
answered 3 hours ago
SecropSecrop
1,893614
answered 3 hours ago
SecropSecrop
1,893614
1,893614
$begingroup$
It doesn't give any output with vector type now.
$endgroup$
– Oleksiy Plotnyts'kyy
3 hours ago
$begingroup$
Ahh.. so that's what the cast frompointtofloatis doing..I couldn't work it out...
$endgroup$
– Robin Betts
2 hours ago
2
$begingroup$
@OleksiyPlotnyts'kyy, ohh, osl optimizations.. I'm changing the script ;)
$endgroup$
– Secrop
2 hours ago
add a comment |
$begingroup$
It doesn't give any output with vector type now.
$endgroup$
– Oleksiy Plotnyts'kyy
3 hours ago
$begingroup$
Ahh.. so that's what the cast frompointtofloatis doing..I couldn't work it out...
$endgroup$
– Robin Betts
2 hours ago
2
$begingroup$
@OleksiyPlotnyts'kyy, ohh, osl optimizations.. I'm changing the script ;)
$endgroup$
– Secrop
2 hours ago
$begingroup$
It doesn't give any output with vector type now.
$endgroup$
– Oleksiy Plotnyts'kyy
3 hours ago
$begingroup$
It doesn't give any output with vector type now.
$endgroup$
– Oleksiy Plotnyts'kyy
3 hours ago
$begingroup$
Ahh.. so that's what the cast from
point to float is doing..I couldn't work it out...$endgroup$
– Robin Betts
2 hours ago
$begingroup$
Ahh.. so that's what the cast from
point to float is doing..I couldn't work it out...$endgroup$
– Robin Betts
2 hours ago
2
2
$begingroup$
@OleksiyPlotnyts'kyy, ohh, osl optimizations.. I'm changing the script ;)
$endgroup$
– Secrop
2 hours ago
$begingroup$
@OleksiyPlotnyts'kyy, ohh, osl optimizations.. I'm changing the script ;)
$endgroup$
– Secrop
2 hours ago
add a comment |
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$begingroup$
How big is your sphere? Is the sphere's origin at its center? Where's the file that shows that problem? Which version of blender are you using? Gosh, so many questions... This is because the Position gives exactly the world coordinates of the point being sampled.
$endgroup$
– Secrop
3 hours ago