public static CameraMatricesExpressions GetMatricesExpressions(IEnumerable <VFXNamedExpression> expressions, VFXCoordinateSpace cameraSpace, VFXCoordinateSpace outputSpace)
{
var fov = expressions.First(e => e.name == "Camera_fieldOfView");
var aspect = expressions.First(e => e.name == "Camera_aspectRatio");
var near = expressions.First(e => e.name == "Camera_nearPlane");
var far = expressions.First(e => e.name == "Camera_farPlane");
var cameraMatrix = expressions.First(e => e.name == "Camera_transform");
var isOrtho = expressions.First(e => e.name == "Camera_orthographic");
var orthoSize = expressions.First(e => e.name == "Camera_orthographicSize");
var lensShift = expressions.First(e => e.name == "Camera_lensShift");
VFXExpression ViewToVFX = cameraMatrix.exp;
if (cameraSpace == VFXCoordinateSpace.World && outputSpace == VFXCoordinateSpace.Local)
{
ViewToVFX = new VFXExpressionTransformMatrix(VFXBuiltInExpression.WorldToLocal, cameraMatrix.exp);
}
else if (cameraSpace == VFXCoordinateSpace.Local && outputSpace == VFXCoordinateSpace.World)
{
ViewToVFX = new VFXExpressionTransformMatrix(VFXBuiltInExpression.LocalToWorld, cameraMatrix.exp);
}
VFXExpression VFXToView = new VFXExpressionInverseTRSMatrix(ViewToVFX);
VFXExpression ViewToClip = new VFXExpressionBranch(isOrtho.exp,
VFXOperatorUtility.GetOrthographicMatrix(orthoSize.exp, aspect.exp, near.exp, far.exp),
VFXOperatorUtility.GetPerspectiveMatrix(fov.exp, aspect.exp, near.exp, far.exp, lensShift.exp));
VFXExpression ClipToView = new VFXExpressionInverseMatrix(ViewToClip);
return(new CameraMatricesExpressions()
{
ViewToVFX = new VFXNamedExpression(ViewToVFX, "ViewToVFX"),
VFXToView = new VFXNamedExpression(VFXToView, "VFXToView"),
ViewToClip = new VFXNamedExpression(ViewToClip, "ViewToClip"),
ClipToView = new VFXNamedExpression(ClipToView, "ClipToView"),
});
}
protected override VFXExpression[] BuildExpression(VFXExpression[] inputExpression)
{
// Offset to compensate for the numerous custom camera generated expressions
_customCameraOffset = 0;
// Get the extra number of expressions if a custom camera input is used
if (camera == CameraMode.Custom)
{
_customCameraOffset = GetInputSlot(0).children.Count() - 1;
}
// List to gather all output expressions as their number can vary
List <VFXExpression> outputs = new List <VFXExpression>();
// Camera expressions
var expressions = Block.CameraHelper.AddCameraExpressions(GetExpressionsFromSlots(this), camera);
Block.CameraMatricesExpressions camMatrices = Block.CameraHelper.GetMatricesExpressions(expressions);
var Camera_depthBuffer = expressions.First(e => e.name == "Camera_depthBuffer").exp;
var CamPixDim = expressions.First(e => e.name == "Camera_pixelDimensions").exp;
// Set uvs
VFXExpression uv = VFXValue.Constant <Vector2>();
// Determine how the particles are spawned on the screen
switch (mode)
{
case PositionMode.Random:
// Random UVs
uv = new VFXExpressionCombine(VFXOperatorUtility.FixedRandom(0, VFXSeedMode.PerParticle), VFXOperatorUtility.FixedRandom(1, VFXSeedMode.PerParticle));
break;
case PositionMode.Sequential:
// Pixel perfect spawn
VFXExpression gridStep = inputExpression[inputSlots.IndexOf(inputSlots.First(o => o.name == "GridStep")) + _customCameraOffset];
VFXExpression sSizeX = new VFXExpressionCastFloatToUint(CamPixDim.x / new VFXExpressionCastUintToFloat(gridStep));
VFXExpression sSizeY = new VFXExpressionCastFloatToUint(CamPixDim.y / new VFXExpressionCastUintToFloat(gridStep));
VFXExpression nbPixels = sSizeX * sSizeY;
VFXExpression particleID = new VFXAttributeExpression(VFXAttribute.ParticleId);
VFXExpression id = VFXOperatorUtility.Modulo(particleID, nbPixels);
VFXExpression shift = new VFXExpressionBitwiseRightShift(gridStep, VFXValue.Constant <uint>(1));
VFXExpression U = VFXOperatorUtility.Modulo(id, sSizeX) * gridStep + shift;
VFXExpression V = id / sSizeX * gridStep + shift;
VFXExpression ids = new VFXExpressionCombine(new VFXExpressionCastUintToFloat(U), new VFXExpressionCastUintToFloat(V));
uv = new VFXExpressionDivide(ids + VFXOperatorUtility.CastFloat(VFXValue.Constant(0.5f), VFXValueType.Float2), CamPixDim);
break;
case PositionMode.Custom:
// Custom UVs
uv = inputExpression[inputSlots.IndexOf(inputSlots.FirstOrDefault(o => o.name == "UVSpawn")) + _customCameraOffset];
break;
}
VFXExpression projpos = uv * VFXValue.Constant <Vector2>(new Vector2(2f, 2f)) - VFXValue.Constant <Vector2>(Vector2.one);
VFXExpression uvs = new VFXExpressionCombine(uv.x * CamPixDim.x, uv.y * CamPixDim.y, VFXValue.Constant(0f), VFXValue.Constant(0f));
// Get depth
VFXExpression depth = new VFXExpressionExtractComponent(new VFXExpressionLoadTexture2DArray(Camera_depthBuffer, uvs), 0);
if (SystemInfo.usesReversedZBuffer)
{
depth = VFXOperatorUtility.OneExpression[depth.valueType] - depth;
}
VFXExpression isAlive = VFXValue.Constant(true);
// Determine how the particles are culled
switch (cullMode)
{
case CullMode.None:
// do nothing
break;
case CullMode.Range:
VFXExpression depthRange = inputExpression[inputSlots.IndexOf(inputSlots.LastOrDefault(o => o.name == "DepthRange")) + _customCameraOffset];
VFXExpression nearRangeCheck = new VFXExpressionCondition(VFXCondition.Less, depth, depthRange.x);
VFXExpression farRangeCheck = new VFXExpressionCondition(VFXCondition.Greater, depth, depthRange.y);
VFXExpression logicOr = new VFXExpressionLogicalOr(nearRangeCheck, farRangeCheck);
isAlive = new VFXExpressionBranch(logicOr, VFXValue.Constant(false), VFXValue.Constant(true));
break;
case CullMode.FarPlane:
VFXExpression farPlaneCheck = new VFXExpressionCondition(VFXCondition.GreaterOrEqual, depth, VFXValue.Constant(1f) - VFXValue.Constant(Mathf.Epsilon));
isAlive = new VFXExpressionBranch(farPlaneCheck, VFXValue.Constant(false), VFXValue.Constant(true));
break;
}
VFXExpression zMultiplier = inputExpression[inputSlots.IndexOf(inputSlots.First(o => o.name == "ZMultiplier")) + _customCameraOffset];
VFXExpression clipPos = new VFXExpressionCombine(projpos.x, projpos.y,
depth * zMultiplier * VFXValue.Constant(2f) - VFXValue.Constant(1f),
VFXValue.Constant(1f)
);
VFXExpression clipToVFX = new VFXExpressionTransformMatrix(camMatrices.ViewToVFX.exp, camMatrices.ClipToView.exp);
VFXExpression vfxPos = new VFXExpressionTransformVector4(clipToVFX, clipPos);
VFXExpression position = new VFXExpressionCombine(vfxPos.x, vfxPos.y, vfxPos.z) / VFXOperatorUtility.CastFloat(vfxPos.w, VFXValueType.Float3);
VFXExpression color = VFXValue.Constant <Vector4>();
// Assigning the color output to the corresponding color buffer value
if (inheritSceneColor)
{
VFXExpression Camera_colorBuffer = expressions.First(e => e.name == "Camera_colorBuffer").exp;
VFXExpression tempColor = new VFXExpressionLoadTexture2DArray(Camera_colorBuffer, uvs);
color = new VFXExpressionCombine(tempColor.x, tempColor.y, tempColor.z, VFXValue.Constant(1.0f));
}
// Add expressions in the right output order
outputs.Add(position);
if (inheritSceneColor)
{
outputs.Add(color);
}
if (cullMode != CullMode.None)
{
outputs.Add(isAlive);
}
return(outputs.ToArray());
}