gBuffer.Velocity can't extract from gBuffer

I add new texture like a

Texture2D ScreenSpaceAOTexture;
SamplerState ScreenSpaceAOTextureSampler;

in DefferedShadingCommon.usf and write they in PostProcessing.cpp. Create Sample Shader and write velocity data like in (PostProcessMotionBlur.usf) visualize velocity to my texture. Then create new float4 data in ScreenSpaceData in shaders. Return then data in material template in new menu in SceneTexture node.

Thanks Bro,
Can you tell me more details about this?

I use this code in shader custom node:

MaterialFloat2 UV = MaterialFloat2(ScreenAlignedPosition(Parameters.ScreenPosition).xy);
FScreenSpaceData ScreenSpaceData = GetScreenSpaceData(UV, false);
return ScreenSpaceData.GBuffer.Velocity.xy;

Can’t get gBuffer.Velocity. No error but just black.
But I use VisualizeTexture velocity in cmd. it can show velocity in a little window.
Can any one teach me how to do it?

we talk about it at forum, Please visit it:

Please help…

If I enter the same in a custom node I get the errors:
[SM5] /Engine/Generated/Material.ush(1270,77-92): error X3000: unrecognized identifier ‘FScreenSpaceData’
[SM5] /Engine/Generated/Material.ush(1270,94-108): error X3000: unrecognized identifier ‘ScreenSpaceData’

What did you do get rid of them?