transformation

来源： https://stackoverflow.com/questions/63569343/how-can-i-rotate-the-pclcropbox-wrt-its-own-particular-axis-rather-than-global

来源： https://stackoverflow.com/questions/63569343/how-can-i-rotate-the-pclcropbox-wrt-its-own-particular-axis-rather-than-global

问题 I have been using Spark + Python to finish some works, it's great, but I have a question in my mind: where is the spark job of transformation and action done? Is transformation job done in Spark Master ( or Driver ) while action job is done in Workers ( Executors ), or both of them are done in Workers ( Executors ) Thanks 回答1: Workers (aka slaves) are running Spark instances where executors live to execute tasks. Transformations are performed at the worker, when the action method is called

问题 I am playing with bitmap on Android and I am facing an issue when selecting an area on the bitmap using the 4 points. Not all the sets of 4 points work for me. In some cases, the result is just a blank bitmap instead of the cropped bitmap (like in the picture) and there is not any error in logcat(even memory error). Here is the basic code I used to do the transformation. import android.app.Activity; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics

问题 #point no.1 after transforming points via the projection matrix , we end up with the point in the range [-1,1], but, in the depth testing chapter , the author mentions that F_depth = 1/z-1/far /(1/near - 1/far) converts the view space coordinates i.e. z=z eye is transformed from [-1,1] to [0,1] . I've followed this thread, and one of the members tell me that the formula F_depth is actually a composition for a series of steps done, and outlines this step: z_Clip = C*z_eye+D*W_eye w_Clip = -z

问题 #point no.1 after transforming points via the projection matrix , we end up with the point in the range [-1,1], but, in the depth testing chapter , the author mentions that F_depth = 1/z-1/far /(1/near - 1/far) converts the view space coordinates i.e. z=z eye is transformed from [-1,1] to [0,1] . I've followed this thread, and one of the members tell me that the formula F_depth is actually a composition for a series of steps done, and outlines this step: z_Clip = C*z_eye+D*W_eye w_Clip = -z

问题 I have CVPixelBufferRef from an AVAsset . I'm trying to apply a CIFilter to it. I use these lines: CVPixelBufferRef pixelBuffer = ... CVPixelBufferRef newPixelBuffer = // empty pixel buffer to fill CIContex *context = // CIContext created from EAGLContext CGAffineTransform preferredTransform = // AVAsset track preferred transform CIImage *phase1 = [CIImage imageWithCVPixelBuffer:pixelBuffer]; CIImage *phase2 = [phase1 imageByApplyingTransform:preferredTransform]; CIImage *phase3 = [self

问题 I have CVPixelBufferRef from an AVAsset . I'm trying to apply a CIFilter to it. I use these lines: CVPixelBufferRef pixelBuffer = ... CVPixelBufferRef newPixelBuffer = // empty pixel buffer to fill CIContex *context = // CIContext created from EAGLContext CGAffineTransform preferredTransform = // AVAsset track preferred transform CIImage *phase1 = [CIImage imageWithCVPixelBuffer:pixelBuffer]; CIImage *phase2 = [phase1 imageByApplyingTransform:preferredTransform]; CIImage *phase3 = [self

问题 I have CVPixelBufferRef from an AVAsset . I'm trying to apply a CIFilter to it. I use these lines: CVPixelBufferRef pixelBuffer = ... CVPixelBufferRef newPixelBuffer = // empty pixel buffer to fill CIContex *context = // CIContext created from EAGLContext CGAffineTransform preferredTransform = // AVAsset track preferred transform CIImage *phase1 = [CIImage imageWithCVPixelBuffer:pixelBuffer]; CIImage *phase2 = [phase1 imageByApplyingTransform:preferredTransform]; CIImage *phase3 = [self

问题 float curpos = player.transform.position.magnitude; float targetpos=GameObject.Find ("target").transform.position.magnitude; float percentDist = (curCarpos / targetpos) * 100; What I want to do is calculate percentage along the way from current point which is always moving to end point, starting from zero and once it reaches it should be 100. For some reason it is starting from 14% decreasing to 0% and then starting from 0%-99%. 回答1: You do it all wrong. Vectors magnitude in this case it is