SQL Server 2012 :: Variables That Are Not Null Put In TVP?

I have three variables

DECLARE @QuantityID uniqueidentifier,
@LengthID uniqueidentifier,
@CostID uniqueidentifier

They are sent to the sproc as null. Since they could be null I need to exclude them from posting to a temp table

Example

DECLARE @QuantityID uniqueidentifier,
@LengthID uniqueidentifier,
@CostID uniqueidentifier
SET @CostID = NEWID()
SELECT @QuantityID as ID UNION ALL
SELECT @LengthID UNION ALL
SELECT @CostID

Two values are null. I want those excluded from this table

Here is the example of what I am trying to do:

DECLARE @QuantityID uniqueidentifier,
@LengthID uniqueidentifier,
@CostID uniqueidentifier
DECLARE @Temp as Table (id uniqueidentifier NOT NULL Primary key)
SET @CostID = NEWID()
INSERT INTO @Temp
SELECT @QuantityID as ID UNION ALL
SELECT @LengthID UNION ALL
SELECT @CostID

How do I insert into @Temp only non null values?