bool InstanceSurfaceScatterBuilder::testPositionPickAndAddObject(Scene& scene, const Point& position, RNG& rng, TestPosInfo& posInfo)
{
Ray occlusionRay(position, Normal(0.0f, -1.0f, 0.0f), RAY_ALL);
// BVH intersectors depend on signed inf values resulting from div-by-0 for axis-aligned rays...
occlusionRay.calculateInverseDirection();
HitResult hitResult;
float t = 1000.0f;
if (scene.didHitObject(occlusionRay, t, hitResult))
{
if (hitResult.hitPoint.y < m_minimumCutoff)
return false;
Object* pSrcObject = posInfo.pCurrentSelectedObject;
Point newPoint = position;
newPoint.y -= t;
unsigned int randomIndex = 0;
if (posInfo.randomlyPickObject)
{
// TODO: Given that we're picking a random index AND a random location, we don't get the best
// distribution here...
if (posInfo.doSwitchover)
{
if (posInfo.switchCount < m_lastObjectSwitchover)
{
randomIndex = rng.randomInt(posInfo.numSelectedItems - 1);
pSrcObject = SelectionManager::instance().getSelection().getSelectedObjectAtIndex(randomIndex);
}
else
{
// pick the last object
randomIndex = posInfo.numSelectedItems - 1;
pSrcObject = SelectionManager::instance().getSelection().getSelectedObjectAtIndex(randomIndex);
}
}
else
{
// just randomly pick...
randomIndex = rng.randomInt(posInfo.numSelectedItems);
pSrcObject = SelectionManager::instance().getSelection().getSelectedObjectAtIndex(randomIndex);
}
// need to update the height of the object
BoundaryBox shapeBBox = pSrcObject->getTransformedBoundaryBox();
posInfo.heightOffset = shapeBBox.getExtent().y * 0.5f;
}
float scaleVariation = 1.0f;
if (posInfo.scaleVariation)
{
// scale variation can be larger or smaller than current object, split around the middle
float halfVariation = m_uniformScaleVariation * 0.5f;
scaleVariation = 1.0f - halfVariation + (m_uniformScaleVariation * rng.randomFloat());
}
float localHeightOffset = posInfo.heightOffset;
if (posInfo.scaleVariation)
{
localHeightOffset *= scaleVariation;
}
newPoint.y += localHeightOffset; // centre the object's bbox on the surface that was hit
// TODO: an option to ratio this based on the surface flatness amount, so that objects on a flat surface
// don't have as much as an offset, whereas objects on a steep incline (trees for example) have more of an offset
newPoint.y += m_surfaceYOffset;
Object* pNewObject = NULL;
if (!posInfo.shouldMakeBakedInstances)
{
pNewObject = pSrcObject->clone();
if (m_alternatingMaterials)
{
Material* pMat = posInfo.aMaterials[posInfo.altMaterialIndex];
pNewObject->setMaterial(pMat);
posInfo.altMaterialIndex++;
if (posInfo.altMaterialIndex >= m_numMaterials)
posInfo.altMaterialIndex = 0;
}
}
else
{
if (posInfo.randomlyPickObject)
{
pNewObject = new CompoundInstance(posInfo.aMultipleSrcCO[randomIndex]);
}
else
{
pNewObject = new CompoundInstance(posInfo.pSrcCOForBakedInstances);
}
}
pNewObject->setPosition(Vector(newPoint.x, newPoint.y, newPoint.z));
if (posInfo.scaleVariation)
{
float currentUScale = pNewObject->transform().getUniformScale();
pNewObject->transform().setUniformScale(currentUScale * scaleVariation);
}
if (m_alignToSurface)
{
// work out what the rotation should be to make it roughly flat on the surface - this won't be physically-accurate, but it's
// a good starting point
Quaternion rotateQ = Quaternion::fromDirections(Normal(0.0f, 1.0f, 0.0f), hitResult.geometryNormal);
Matrix4 rotateM = rotateQ.toMatrix();
Vector rotation = rotateM.getRotationYXZ();
if (m_randomYRotation)
{
rotation.y = rng.randomFloat() * 360.0f;
}
pNewObject->setRotation(rotation);
}
else
{
if (m_randomYRotation)
{
pNewObject->setRotation(Vector(0.0f, rng.randomFloat() * 360.0f, 0.0f));
}
}
if (m_drawAsBBox)
pNewObject->setDisplayType(eBoundaryBox);
sprintf(posInfo.szName, "ScatteredOb_%d", posInfo.createdCount); // calling function needs to increment this
pNewObject->setName(posInfo.szName, false);
if (m_addToGroup)
{
posInfo.pNewCO->addObject(pNewObject, false);
}
else
{
addObject(scene, pNewObject);
}
}
return true;
}
