How can I change RGB values of pcl::PointXYZRGBA?

问题:

I have a point of the type pcl::PointXYZRGBA. How can I assign/change its rgb values?

For changing xyz coordinates, I can simply do point.x = some_value.

回答1:

Or just use

point.r = 255;
point.b = 0;
point.g = 0;
point.a = 255;

回答2:

You can use pcl::PointXYZRGB instead of pcl::PointXYZRGBA. I think they both do the same. And then to color a point red (255,0,0), you can do:

pcl::PointXYZRGB point = pcl::PointXYZRGB(255, 0, 0);

And the xyz-coordinates can then be assigned respectively:

point.x = x;
point.y = y;
point.z = z;

EDIT: Or if you have to stick with pcl::PointXYZRGBA, you can do

pcl::PointXYZRGBA point;
uint8_t r = 255;
uint8_t g = 0;
uint8_t b = 0;
int32_t rgb = (r << 16) | (g << 8) | b; 
point.rgba = *(float *)(&rgb); // makes the point red