2 inputs on a custom Pop?

[Daniel]

Hello, I'd like to access points feeding the second input of a custom Pop but I don't see how that's done. Looks like in Sops you use "inputGeo" to grab the second inputs data but I don't see the equiv in pops. There aren't many pops that use a second input.. most fetch geometry from a sop path.. is that the way I should go? my second input isn't dynamic partical data so it wouldn't be a problem I guess

still would like to know if the second input thing is possible

thnx

Daniel

[Guest xionmark]

Hi Daniel,

I'm not sure if you were asking how to get your POP to accept two inputs or how to grab the geometry coming from the second input. I don't have access to any POP source code at the moment but here's a bit of CHOP code:

void
newChopOperator(OP_OperatorTable *table)
{
 table->addOperator(
    new OP_Operator("file_out",             // Internal name
    "File Out",                     // UI name
    CHOP_file_out::myConstructor,  // CHOP constructor
    &CHOP_file_out::myTemplatePair, // Parameters
    1,                          // Min # of inputs
    2,                          // Max # of inputs
    &CHOP_file_out::myVariablePair) // Local variables
);
}

I believe for any OP the declaration above is almost the same; notice the next to the last line for Max # of inputs.

As for grabbing SOP geo, I think you can use the "getSopGeo (OP_Node *sop, OP_Context &context)" method. And I think the duplicateSource() and getInput() works in POP land too ... but I'm not in the office and am trying to pull (from a VERY tired) memory ...

Hope that helps, I can look into it further Saturday if you haven't figured it out.

Take care,

Mark

[mwin]

Hello

Actually , I'm doing somehting similar and I have a few questions regarding this topic.

By looking at the sample codes provided by SESI, data.getDetail () returns the geo info for the source. But let's say that I have a collision object and I want to feed that into my pop like in Collision pop.

My first question is how can I look for that specific colliion sop from POP and

the second question is starting from I have heard, starting from Houdini 8.0.387 and onwards getSopGeo() method is obsolete. If that's the case, which method is available to get the handle for the GU_Detail.?

Thanks.

Hi Daniel,

I'm not sure if you were asking how to get your POP to accept two inputs or how to grab the geometry coming from the second input. I don't have access to any POP source code at the moment but here's a bit of CHOP code:

void
newChopOperator(OP_OperatorTable *table)
{
 table->addOperator(
	new OP_Operator("file_out",			 // Internal name
	"File Out",					 // UI name
	CHOP_file_out::myConstructor,  // CHOP constructor
	&CHOP_file_out::myTemplatePair, // Parameters
	1,						  // Min # of inputs
	2,						  // Max # of inputs
	&CHOP_file_out::myVariablePair) // Local variables
);
}

I believe for any OP the declaration above is almost the same; notice the next to the last line for Max # of inputs.

As for grabbing SOP geo, I think you can use the "getSopGeo (OP_Node *sop, OP_Context &context)" method. And I think the duplicateSource() and getInput() works in POP land too ... but I'm not in the office and am trying to pull (from a VERY tired) memory ...

Hope that helps, I can look into it further Saturday if you haven't figured it out.

Take care,

Mark

Edited September 21, 2007 by mwin

[edward]

Well, first you need to have some way to specify the path to your SOP. The easiest way is to have a PRM_STRING parameter for this with the extended type PRM_TYPE_DYNAMIC_PATH. So then after you evaluate the parameter to get your sop path, you find it like this:

SOP_Node *sop = findNode(my_sop_path);

if (sop == NULL)

// flag error as path is invalid.

Now to obtain the geometry, you should obtain a read lock to it like so (see GU_DetailHandle.h)

GU_DetailHandleAutoReadLock gdh(sop->getCookedGeoHandle());

GU_Detail *sop_gdp = gdh.getGdp();

Now you can use sop_gdp as long as gdh exists. When gdh is destructed, the lock will automatically be released.

[mwin]

cheers Ed!

I'll give it a try.

Well, first you need to have some way to specify the path to your SOP. The easiest way is to have a PRM_STRING parameter for this with the extended type PRM_TYPE_DYNAMIC_PATH. So then after you evaluate the parameter to get your sop path, you find it like this:

SOP_Node *sop = findNode(my_sop_path);

if (sop == NULL)

// flag error as path is invalid.

Now to obtain the geometry, you should obtain a read lock to it like so (see GU_DetailHandle.h)

GU_DetailHandleAutoReadLock gdh(sop->getCookedGeoHandle());

GU_Detail *sop_gdp = gdh.getGdp();

Now you can use sop_gdp as long as gdh exists. When gdh is destructed, the lock will automatically be released.

[mwin]

Hi Ed,

findNode(sopName) returns only OP_Node*.

OP_Node* OP_Node::findNode ( const char * path ) const

so i can't use getCookedGeoHandle() which is a member of SOP_Node.

Is there a way to convert from OP_Node to SOP_Node type?

Cheers.

[edward]

SOP_Node *sop = CAST_SOPNODE(findNode(my_sop_path));