C++ ViewExp::MapScreenToWorldRay方法代码示例

BOOL
TrackMouseCallBack::point_on_obj(ViewExp& vpt, IPoint2 m, Point3& pt, Point3 &norm)
{
	if ( ! vpt.IsAlive() )
	{
		// why are we here
		DbgAssert(!_T("Invalid viewport!"));
		return FALSE;
	}

	// computes the normal ray at the point of intersection
	Ray ray, world_ray;
	float at, best_dist = 0.0f;
	TimeValue t = MAXScript_time();	
	Object *obj = NULL;
	Matrix3 obtm, iobtm;
	Point3 testNorm;

	BOOL found_hit = FALSE;
	
	vl->face_num_val = vl->face_bary = &undefined;
	hit_node = NULL;

	// Calculate a ray from the mouse point
	vpt.MapScreenToWorldRay(float(m.x), float(m.y), world_ray);

	for( int i=(nodeTab.Count()-1); i>=0; i-- ) {
		// Get the object from the node
		INode* node = nodeTab[i];
		ObjectState os = node->EvalWorldState(t);
		obj = os.obj;	

		// Back transform the ray into object space.
		obtm	= node->GetObjectTM(t);
		iobtm	= Inverse(obtm);
		ray.p   = iobtm * world_ray.p;
		ray.dir = VectorTransform(iobtm, world_ray.dir);
		
		// See if we hit the object
		if (obj->IsSubClassOf(triObjectClassID))
		{
			TriObject*  tobj = (TriObject*)obj;
			DWORD		fi;
			Point3		bary;
			if (tobj->mesh.IntersectRay(ray, at, testNorm, fi, bary)  &&
			   ((!found_hit) || (at<=best_dist)) )
			{
				// Calculate the hit point and transform everything back into world space.
				// record the face index and bary coord
				best_dist = at;
				pt = ray.p + ray.dir * at;
				pt = pt * obtm;
				norm = Normalize(VectorTransform(obtm, testNorm));
				vl->face_num_val = Integer::intern(fi + 1);
				vl->face_bary = new Point3Value(bary);
				hit_node = node;
				found_hit = TRUE;
			}
		}
		else if (obj->IntersectRay(t, ray, at, testNorm)  &&
				((!found_hit) || (at<=best_dist)) )
		{
			// Calculate the hit point and transform everything back into world space.
			best_dist = at;
			pt = ray.p + ray.dir * at;
			pt = pt * obtm;
			norm = Normalize(VectorTransform(obtm, testNorm));
			hit_node = node;
			found_hit = TRUE;
		}
	}
	if( found_hit ) return TRUE;

	// Failed to find a hit on any node, look at the Normal Align Vector for the first node
	if ((obj!=NULL) && obj->NormalAlignVector(t, pt, testNorm)) // See if a default NA vector is provided
	{
		pt   = pt * obtm;
		norm = Normalize(VectorTransform(obtm, testNorm));
		return TRUE;
	}
	else
		return FALSE;
}

void TweakMouseProc::ComputeNewUVW(ViewExp& vpt, IPoint2 m)
{
	if ( ! vpt.IsAlive() )
	{
		// why are we here
		DbgAssert(!_T("Invalid viewport!"));
		return;
	}

	Ray r;
	vpt.MapScreenToWorldRay ((float) m.x, (float) m.y, r);
	TimeValue t = GetCOREInterface()->GetTime();
	Matrix3 tm = mod->GetMeshTopoDataNode(mHitLDIndex)->GetObjectTM(t);
	Matrix3 itm = Inverse(tm);

	r.p = r.p * itm;
	r.dir = VectorTransform(r.dir,itm);

	//intersect our ray with that face and get our new bary coords

	Point3 n = mHitLD->GetGeomFaceNormal(mHitFace);

	Point3 p1, p2, p3;

	p1 = mHitP[0];
	p2 = mHitP[1];
	p3 = mHitP[2];

	Point3  p, bry;
	float d, rn, a; 

	// See if the ray intersects the plane (backfaced)
	rn = DotProd(r.dir,n);
	if (rn > -0.0001) return;

	// Use a point on the plane to find d
	Point3 v1 = p1;
	d = DotProd(v1,n);

	// Find the point on the ray that intersects the plane
	a = (d - DotProd(r.p,n)) / rn;

	// Must be positive...
	if (a < 0.0f) return ;



	// The point on the ray and in the plane.
	p = r.p + a*r.dir;

	// Compute barycentric coords.
	bry = BaryCoords(p1,p2,p3,p);  // DbgAssert(bry.x + bry.y+ bry.z = 1.0) 

	Point3 uvw = mHitUVW[0] * bry.x + mHitUVW[1] * bry.y + mHitUVW[2] * bry.z;
	Point3 v = uvw - mSourceUVW;
	v *= -1.0f;
	mFinalUVW = mSourceUVW + v;
	mHitLD->SetTVVert(GetCOREInterface()->GetTime(),mHitTVVert,mFinalUVW,mod);

	mod->NotifyDependents(FOREVER, PART_TEXMAP, REFMSG_CHANGE);
	mod->InvalidateView();
	if (mod->ip) 
		mod->ip->RedrawViews(mod->ip->GetTime());

}

//.........这里部分代码省略.........

			Box2D b = lmesh->boundingBoxList[faceIndex];
			if ( (hitPoint.x >= b.min.x) && (hitPoint.x <= b.max.x) &&
				 (hitPoint.y >= b.min.y) && (hitPoint.y <= b.max.y) )
				{
//now check bary coords
				Point3 a,b,c;
				a = tempVerts[tempFaces->v[0]];
				b = tempVerts[tempFaces->v[1]];
				c = tempVerts[tempFaces->v[2]];
				Point3 az,bz,cz,hitPointZ;
				az = a;
				bz = b;
				cz = c;
				az.z = 0.0f;
				bz.z = 0.0f;
				cz.z = 0.0f;
				hitPointZ = hitPoint;
				hitPointZ.z = 0.0f;
	
				Point3 bry;
				bry = BaryCoords(az, bz, cz, hitPointZ);
//if inside bary find the the z point			
				if (!( (bry.x<0.0f || bry.x>1.0f || bry.y<0.0f || bry.y>1.0f || bry.z<0.0f || bry.z>1.0f) ||
					(fabs(bry.x + bry.y + bry.z - 1.0f) > EPSILON) ))
					{
					float tz = a.z * bry.x + b.z * bry.y + c.z * bry.z; 
					if ( (tz > z ) || (hit == FALSE) )  
						{
						z = tz;
						findex = faceIndex;
						nindex = nodeIndex;
						bary = bry;
						finalZ = z;
						smgroup = tempFaces->getSmGroup();
						}
					hit = TRUE;
					}
				}
			}
		}	
	}
if (hit)
	{
	Point3 a,b,c;
	int ia,ib,ic;
	LightMesh *lmesh = meshList[nindex];
	Point3 *tempVerts = lmesh->vertsWorldSpace.Addr(0);
	Face *tempFaces = lmesh->faces.Addr(findex);

	ia = tempFaces->v[0];
	ib = tempFaces->v[1];
	ic = tempFaces->v[2];
	a = tempVerts[ia];
	b = tempVerts[ib];
	c = tempVerts[ic];

	ViewExp *vpt = GetCOREInterface()->GetActiveViewport();

	Ray worldRay;
//	vpt->GetAffineTM(tm);
	vpt->MapScreenToWorldRay((float) m.x, (float) m.y, worldRay);
	GetCOREInterface()->ReleaseViewport(vpt);

//intersect ray with the hit face

		// See if the ray intersects the plane (backfaced)
	norm = Normalize((b-a)^(c-b));

	float rn = DotProd(worldRay.dir,norm);
		
	// Use a point on the plane to find d
	float d = DotProd(a,norm);

	// Find the point on the ray that intersects the plane
	float ta = (d - DotProd(worldRay.p,norm)) / rn;


		// The point on the ray and in the plane.
	p = worldRay.p + ta*worldRay.dir;

		// Compute barycentric coords.
	bary = BaryCoords(a, b, c, p);

	finalZ  = ta;

//	p = a * bary.x +  b * bary.y +  c * bary.z;
	p = p * meshList[nindex]->toLocalSpace;

	norm = VectorTransform(meshList[nindex]->toLocalSpace,norm);
	toWorldTm = meshList[nindex]->toWorldSpace;

	


	}

return hit;

}