xsimrAttributeData Struct
Reference
#include <xsi_miuserdata_defs.h>
A structure containing the information for a single attribute.
Each attribute has a name and a type. The tag points to a miUserdata blob that contains a flat array of xsimrPointCloudData::nb_particles attribute values.
miTRUE, then all the attribute entries are the
same value and therefore only the first attribute entry is valid to
conserve space.
miScalar getSizeAtIndex( siParticleAttribute *attr, miUint pid, miUint index )
{
miUserdata *data_ptr;
miScalar *size_ptr;
miScalar result;
if( index >= attr->count )
index = attr->count - 1;
data_ptr = (miUserdata *)mi_db_access( attr->tag );
size_ptr = (miScalar *)&data_ptr->parameters[ 0 ];
if( attr->constant )
result = size_ptr[ 0 ];
else
result = size_ptr[ pid * attr->count + index ];
mi_db_unpin( attr_size->tag );
return( result );
}
Public Attributes |
|
| miTag | name |
| xsimrAttributeType | type |
| miBoolean | constant |
| miUint | size |
| miTag | offsets |
| miTag | data |
| miTag | blob_type |
| miTag name |
The name of the attribute. The name is case-insensitive.
The value type of the data. See xsimrAttributeType for which mental ray native data types each enumeration type maps to.
| miBoolean constant |
The constant flag of the data. If all the values of an attribute are the same, then the data is considered to be constant and only one value is stored, which should be used for all points in the cloud. In case of arrays, the same array is used for all points, rather than all values of the array being the same.
miTRUE then the userdata blob
pointed to by xsimrAttributeData::data
will contain only a single value, or a single array of values, and
xsimrAttributeData::offsets,
if defined, will contain only two indices.| miUint size |
The size of the data type in bytes. This is equal to the result
of the sizeof operator on the mental ray data type
used to store the data (see ::siParticleAttributeType).
| miTag offsets |
The userdata tag for the array offset indices of type
miUint32. If the data is an array of arrays, then this
index list will give the index into the data list for the given
particle. This list is one entry larger than the number of
particles so that the length can always be calculated by (
offset[ id + 1 ] - offset[ id ] ) for each particle. If the
data is constant, and that data is an array of arrays, then this
list will contain two entries.
| miTag data |
The userdata tag to the actual value data storage. If the
xsimrAttributeData::offsets
tag is an miNULLTAG then there is only one single
value per particle. Otherwise the data comes in contiguous value
chunks for each particle, and the contents of the offsets data can
be used to index into it for each particle.
| miTag blob_type |
A tag to a string that contains the blob type name if the
type field is set to
xsimrATTRIBUTE_BLOB. For any other type, it is left as a
miNULLTAG.