how can i save a multisample rendertarget in dx9

You have to resolve it to a non-multisampled render target using StretchRect.

Thanks mjp.
That is to say,multisampled render target can't be acess?
I'm making a terrain editor,i want it support many to any textures (like unity 3d,how it do?).
So,i draw the brush textures on a rendertarget ,then save to a texture used to the terrain.
If the rendertarget is non-multisampled ,it is very vague.

Excuse me, but what is the point of using multisampled texture for terrain texturing?

Cheers!

Excuse me, but what is the point of using multisampled texture for terrain texturing?

Cheers!

No point used in the terrain!
The terrain only has one texture that is my rendergarget.
The brush contain on quad mesh and a brush texture.All the brushs render with topview .
And can therrin support many to any textures?Thanks.