getblurP

Context(s)	displace fog light shadow surface

vector  getblurP(float delta)

Returns the position (P) of the current shading point at fractional time delta within the motion blur exposure. When motion blur is disabled, getblurP() will always return the shading position P. When motion blur is enabled, getblurP(0) and getblurP(1) will return the positions at the extent of the shading position’s motion path, with fractional values between 0 and 1 generating other intermediate shading positions. For example, getblurP(0.5) returns the point’s blurred position half-way through the current exposure.

When shading micropolygons, P will always store the initial position of the point (at time = 0). For raytracing, P will store the final position after motion transformation for the sample being shaded - at the time given by the Time global variable in the VEX shading context. If you want to determine the shading position at other times it is necessary to use getblurP.

When using point clouds that were generated at time = 0, you should use getblurP(0) to find the position at the start of the frame’s exposure and then use this position to look up in the point cloud.

For example:

vector p0 = getblurP(0);
int handle = pcopen("pcloud.pc", p0, ...);