VEX functions and inline vopsop

[Macha]

I have 2 questions regarding vex and the inline vopsop.

-Is it possible to define a function in the inlinevop and then call it as well? Something along the lines of:

float f(float x, float y){ return x*y; }
z=f(12.0,23.0);
printf("z:%f ",z);

We can do this with a Vex builder type by putting the functions in the outer code section if I remember correctly. But how about inline vop?

-Is there a way to turn a string into a vex expression? For example, a user would enter "x^2" as a parameter and we could use it as

x^2 

in the code.

Thanks!

Edited May 30, 2012 by Macha

[rdg]

f(float x, float y){ return x*y; }
z=f(12.0,23.0);
printf("z:%f ",z);

You can specify an external header file on the inlineVOP.

As far as I know this can't be part of an HDA section and probably want to sit somewhere in $HOUDINI_PATH/vex/include.

Maybe helps.

[nord3d]

...

-Is there a way to turn a string into a vex expression? For example, a user would enter "x^2" as a parameter and we could use it as

x^2 

in the code.

Thanks!

Hi there,

How about the second question? It is also very interesting to me.

As well as a way to execute a string in the one parameter's field as an expression in other parameter's field. I have tried eval(), but without success.

[Guest mantragora]

Hi there,

How about the second question? It is also very interesting to me.

As well as a way to execute a string in the one parameter's field as an expression in other parameter's field. I have tried eval(), but without success.

Not possible. For things like this you need interpreted/dynamic language. That means that, in Houdini world, Python is your answer.

Edited June 14, 2012 by mantragora

[nord3d]

Thanks, mantragora.

So, it is possible, if use Python instead of HScript, for that parameter fields, I understand you correctly?

[Guest mantragora]

1. You can create your own expressions in "Edit->Aliases and Variables->Expression" Tab. Maybe this is what you are looking for.

2. Why do you need this ? x^2 will not execute pow() function in Python without making comparisons with if:...elif:... so it's still not useful. You can probably add aliases to python classes that will allow something like this, but it will make bigger mess, for you to manage, than help.

[nord3d]

Thank you again, I will think about it...

Why? -For example, in the asset, user could type an expression, which would be executed in the SOP-node inside...