/**
* @file llphysicsshapebuilder.cpp
* @brief Generic system to convert LL(Physics)VolumeParams to physics shapes
*
* $LicenseInfo:firstyear=2001&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#include "llviewerprecompiledheaders.h"
#include "llphysicsshapebuilderutil.h"
/* static */
void LLPhysicsShapeBuilderUtil::determinePhysicsShape( const LLPhysicsVolumeParams& volume_params, const LLVector3& scale, PhysicsShapeSpecification& specOut)
{
const LLProfileParams& profile_params = volume_params.getProfileParams();
const LLPathParams& path_params = volume_params.getPathParams();
specOut.mScale = scale;
const F32 avgScale = ( scale[VX] + scale[VY] + scale[VZ] )/3.0f;
// count the scale elements that are small
S32 min_size_counts = 0;
for (S32 i = 0; i < 3; ++i)
{
if (scale[i] < SHAPE_BUILDER_CONVEXIFICATION_SIZE)
{
++min_size_counts;
}
}
const bool profile_complete = ( profile_params.getBegin() <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale ) &&
( profile_params.getEnd() >= (1.0f - SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale) );
const bool path_complete = ( path_params.getBegin() <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale ) &&
( path_params.getEnd() >= (1.0f - SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale) );
const bool simple_params = ( volume_params.getHollow() <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_HOLLOW/avgScale )
&& ( fabs(path_params.getShearX()) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_SHEAR/avgScale )
&& ( fabs(path_params.getShearY()) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_SHEAR/avgScale )
&& ( !volume_params.isMeshSculpt() && !volume_params.isSculpt() );
if (simple_params && profile_complete)
{
// Try to create an implicit shape or convexified
bool no_taper = ( fabs(path_params.getScaleX() - 1.0f) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_TAPER/avgScale )
&& ( fabs(path_params.getScaleY() - 1.0f) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_TAPER/avgScale );
bool no_twist = ( fabs(path_params.getTwistBegin()) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_TWIST/avgScale )
&& ( fabs(path_params.getTwistEnd()) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_TWIST/avgScale);
// Box
if(
( profile_params.getCurveType() == LL_PCODE_PROFILE_SQUARE )
&& ( path_params.getCurveType() == LL_PCODE_PATH_LINE )
&& no_taper
&& no_twist
)
{
specOut.mType = PhysicsShapeSpecification::BOX;
if ( path_complete )
{
return;
}
else
{
// Side lengths
specOut.mScale[VX] = llmax( scale[VX], SHAPE_BUILDER_MIN_GEOMETRY_SIZE );
specOut.mScale[VY] = llmax( scale[VY], SHAPE_BUILDER_MIN_GEOMETRY_SIZE );
specOut.mScale[VZ] = llmax( scale[VZ] * (path_params.getEnd() - path_params.getBegin()), SHAPE_BUILDER_MIN_GEOMETRY_SIZE );
specOut.mCenter.set( 0.f, 0.f, 0.5f * scale[VZ] * ( path_params.getEnd() + path_params.getBegin() - 1.0f ) );
return;
}
}
// Sphere
if( path_complete
&& ( profile_params.getCurveType() == LL_PCODE_PROFILE_CIRCLE_HALF )
&& ( path_params.getCurveType() == LL_PCODE_PATH_CIRCLE )
&& ( fabs(volume_params.getTaper()) <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_TAPER/avgScale )
&& no_twist
)
{
if ( ( scale[VX] == scale[VZ] )
&& ( scale[VY] == scale[VZ] ) )
{
// perfect sphere
specOut.mType = PhysicsShapeSpecification::SPHERE;
specOut.mScale = scale;
return;
}
else if (min_size_counts > 1)
{
// small or narrow sphere -- we can boxify
for (S32 i=0; i<3; ++i)
{
if (specOut.mScale[i] < SHAPE_BUILDER_CONVEXIFICATION_SIZE)
{
// reduce each small dimension size to split the approximation errors
specOut.mScale[i] *= 0.75f;
}
}
specOut.mType = PhysicsShapeSpecification::BOX;
return;
}
}
// Cylinder
if( (scale[VX] == scale[VY])
&& ( profile_params.getCurveType() == LL_PCODE_PROFILE_CIRCLE )
&& ( path_params.getCurveType() == LL_PCODE_PATH_LINE )
&& ( volume_params.getBeginS() <= SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale )
&& ( volume_params.getEndS() >= (1.0f - SHAPE_BUILDER_IMPLICIT_THRESHOLD_PATH_CUT/avgScale) )
&& no_taper
)
{
if (min_size_counts > 1)
{
// small or narrow sphere -- we can boxify
for (S32 i=0; i<3; ++i)
{
if (specOut.mScale[i] < SHAPE_BUILDER_CONVEXIFICATION_SIZE)
{
// reduce each small dimension size to split the approximation errors
specOut.mScale[i] *= 0.75f;
}
}
specOut.mType = PhysicsShapeSpecification::BOX;
}
else
{
specOut.mType = PhysicsShapeSpecification::CYLINDER;
F32 length = (volume_params.getPathParams().getEnd() - volume_params.getPathParams().getBegin()) * scale[VZ];
specOut.mScale[VY] = specOut.mScale[VX];
specOut.mScale[VZ] = length;
// The minus one below fixes the fact that begin and end range from 0 to 1 not -1 to 1.
specOut.mCenter.set( 0.f, 0.f, 0.5f * (volume_params.getPathParams().getBegin() + volume_params.getPathParams().getEnd() - 1.f) * scale[VZ] );
}
return;
}
}
if ( (min_size_counts == 3 )
// Possible dead code here--who wants to take it out?
|| (path_complete
&& profile_complete
&& ( path_params.getCurveType() == LL_PCODE_PATH_LINE )
&& (min_size_counts > 1 ) )
)
{
// it isn't simple but
// we might be able to convexify this shape if the path and profile are complete
// or the path is linear and both path and profile are complete --> we can boxify it
specOut.mType = PhysicsShapeSpecification::BOX;
specOut.mScale = scale;
return;
}
// Special case for big, very thin objects - bump the small dimensions up to the COLLISION_TOLERANCE
if (min_size_counts == 1 // One dimension is small
&& avgScale > 3.f) // ... but others are fairly large
{
for (S32 i = 0; i < 3; ++i)
{
specOut.mScale[i] = llmax( specOut.mScale[i], COLLISION_TOLERANCE );
}
}
if ( volume_params.shouldForceConvex() )
{
// Server distinguishes between convex of a prim vs isSculpt, but we don't care.
specOut.mType = PhysicsShapeSpecification::USER_CONVEX;
}
// Make a simpler convex shape if we can.
else if (volume_params.isConvex() // is convex
|| min_size_counts > 1 ) // two or more small dimensions
{
specOut.mType = PhysicsShapeSpecification::PRIM_CONVEX;
}
else if (volume_params.isMeshSculpt() &&
// Check overall dimensions, not individual triangles.
(scale.mV[0] < SHAPE_BUILDER_USER_MESH_CONVEXIFICATION_SIZE ||
scale.mV[1] < SHAPE_BUILDER_USER_MESH_CONVEXIFICATION_SIZE ||
scale.mV[2] < SHAPE_BUILDER_USER_MESH_CONVEXIFICATION_SIZE
) )
{
// Server distinguishes between user-specified or default convex mesh, vs server's thin-triangle override, but we don't.
specOut.mType = PhysicsShapeSpecification::PRIM_CONVEX;
}
else if ( volume_params.isSculpt() ) // Is a sculpt of any kind (mesh or legacy)
{
specOut.mType = volume_params.isMeshSculpt() ? PhysicsShapeSpecification::USER_MESH : PhysicsShapeSpecification::SCULPT;
}
else // Resort to mesh
{
specOut.mType = PhysicsShapeSpecification::PRIM_MESH;
}
}