vecvechookattack - not strictly true. If Prince Charles were to exclude himself from the Succession - for example, by converting to Catholicism or marrying a Catholic, or by declaring his opposition to claiming the Throne - then he would also exclude his sons.
If, on the other hand, he was excluded by death, dementia, or some such problem, the line of Succession would pass to his sons. He would only exclude his bloodline by wilfully invalidating his own claim to the Throne.