Re: User data blob from XSI to Mental Ray

["Vince Fortin" <vfortin(at)gmail.com>]

Hope you don't mind, Felix, but I find myself guilty of nosing about
your dump folder once in a while and every time I do find something new and inspiring. How about setting up a RSS feed?

On Tue, Mar 11, 2008 at 1:58 PM, andreas gebhardt <gebhardt(at)betacarotin.de> wrote:

Not sure if this helps but all polygon meshes are sent to MR like this
-> http://www.sukio.de/dump/MR_user_data_blob_location.png
to allow splitting geometry into chunks for better handling triangle
heavy cases.

Amaan Akram wrote:
> Hi Ben,
>
> Thanks very much for sending the code. It seems perfectly
> straightforward, but unfortunately, it does not work for me.
>
> Your code integrated just fine, queried the proper object, but it
> heads straight to the following line of code
>    if( !found_userdata )
>   {
>       mi_error("base object data not found");
>       return( miTRUE );
>   }
>
> This is all a bit new to me and a bit strange. When I put userdata on
> the state->instance object (the geometry shader primitive), I can
> query the userdata just fine at:
> <object_name>/Polygon Mesh_Inst(0)  level.
>
> But when the userdata is placed on an object other than the geo shader
> primitive, the userdata gets placed in <object_name>[i] level. I
> confirmed this by outputting to an .mi file (as suggested by Philipp).
> So when I query an object at this level (<object_name>[i]), I can read
> the userdata just fine.
>
> I must admit I am quite new at this whole shader writing thing & I am
> not able to figure out why userdata gets put in a separate place in
> the scene DAG when we are dealing with object tags other than
> state->instance (which is where the wireframe example in the SDK
> fetches its userdata from).
>
> Thanks!
> Amaan
>
> Ben Rogall wrote:
>> Here's a chunk of code from my Binder addon. It's from the geoshader
>> and the spdl points to the null object with the UserDataBlob (for
>> some reason it's never worked for me to just put the blob under the
>> geoshader primitive itself).
>>
>> ------------------------------------------------------------------------------------------------
>>
>>    miTag dataTag;
>>    miUint dataLabel;
>>    miBoolean found_userdata = miFALSE;
>>    void * p_userdata = NULL;
>>
>>    miTag * objects = &params->objects[ params->i_objects ];
>>
>>    miTag objtag = miNULLTAG;
>>    if(!mi_query(miQ_INST_ITEM, NULL, objects[ 0 ], (void *)&objtag))
>>    {
>>        mi_error("objtag not found");
>>        return( miTRUE );
>>    }
>>
>>    mi_query(miQ_INST_DATA, NULL, objects[ 0 ], (void *)&dataTag);
>>
>>
>>    for( ; ; )
>>    {
>>         if(!mi_query( miQ_DATA_LABEL, NULL, dataTag, (void
>> *)&dataLabel  ))
>>            break;
>>
>>        if( dataLabel == 6789 ) //found userdatablob
>>        {
>>            found_userdata = miTRUE;
>>            mi_query( miQ_DATA_PARAM, NULL, dataTag, &p_userdata ); //
>> get pointer to the blob
>>
>>            break;
>>        }
>>
>>        if( !mi_query( miQ_DATA_NEXT, NULL, dataTag, (void *)&dataTag ) )
>>            break;
>>    }
>>
>>    if( !found_userdata )
>>    {
>>        mi_error("base object data not found");
>>        return( miTRUE );
>>    }
>>
>> -----------------------------------------------------------------------------------------------
>>
>>
>> Hope it helps,
>> Ben
>>
>>
>>
>>
>>
>> Amaan Akram wrote:
>>> Hi Philipp,
>>>
>>> Thanks for replying
>>>
>>> Yes, when I put a userdatablob on the geoshader primitive itself,
>>> and run the following command, I get access to the user data set in
>>> XSI.
>>>     mi_query( miQ_INST_DATA, NULL, state->instance, (void
>>> *)&userdata_tag );
>>>
>>>
>>> My geoshader's SPDL has an object list defined where I go and select
>>> the object with the userdatablob defined. This is what I am doing in
>>> my code where I can't get any user data back
>>>
>>> ------------------------------------------------------------------------------
>>>
>>>    //get miTag to the object selected in the Object List in the
>>> geoshader SPDL
>>>    ...
>>>    ...
>>>    //traverse scene DAG and arrive at the parent of the object instance
>>>    ...
>>>    ...
>>>    miTag child_tag;
>>>    mi_query( miQ_GROUP_KID, NULL, parent_tag, &child_tag,
>>> child_index );
>>>    int tagtype =  mi_db_type(child_type);
>>>    if(tagtype==miSCENE_INSTANCE)
>>>    {
>>>            mi_query( miQ_INST_DATA, NULL, child, (void
>>> *)&userdata_tag );
>>>            if(!userdata_tag)
>>>                mi_warning("null userdata");
>>>    }
>>> ------------------------------------------------------------------------------
>>>
>>>
>>> Any ideas? :(
>>>
>>> Thanks
>>> Amaan
>>>
>>
>> ---
>> Unsubscribe? Mail Majordomo(at)Softimage.COM with the following text in
>> body:
>> unsubscribe xsi
>>
>
>
> ---
> Unsubscribe? Mail Majordomo(at)Softimage.COM with the following text in
> body:
> unsubscribe xsi
>

---
Unsubscribe? Mail Majordomo(at)Softimage.COM with the following text in body:
unsubscribe xsi