Overdraw
When diagnosing performance problems it can be valuable to visualize GPUoverdraw. This can show you where Chrome might be doing more rendering work thannecessary and help you see where you might be able to reduce rendering overhead.
overdraw
The GPU overdraw feedback tool built into Chrome has been inspired by the GPUoverdraw debugfeaturethat exists on Android and developers familiar with that feature will feel athome using this tool to improve the Chrome UI or web pages.
To visualizing GPU overdraw in Chrome navigate to about:flags and enable theShow overdraw feedback experiment. If you are on Chrome OS then it is alsorecommended to disable the Partial swap experiment as that produces output thatis easier to analyze.
When enabled, this tool visualize overdraw by color-coding interface elementsbased on how many elements are drawn underneath. The element colors are hintingat the amount of overdraw on the screen for each pixel, as follows:
Some overdraw is unavoidable. As you are tuning your UI elements or web page,the goal is to arrive at a visualization that shows mostly true colors and 1Xoverdraw in blue. The calculator UI shown above is an example of undesirableamount of GPU overdraw.
There are several strategies you can pursue to reduce or eliminate overdraw. Ifyou are working on the Chrome OS UI then it usually comes down to using fewerAura windows with opacity set to TRANSLUCENT. For Chrome apps and web-pages ingeneral, the following strategies will likely apply:
If you are analyzing GPU overdraw for animations or creating automatedperformance tests then overdraw feedback in the form of trace events can beuseful. See The Trace Event Profiling Tool(about:tracing)for more details about how to record tracing runs. Enable the viz.overdrawtracing category to have Chrome record the amount of overdraw for each frame.The result is presented as a GPU Overdraw counter that changes over time asoverdraw increase or decrease.
The value of the counter is the percentage of overdraw in the last framepresented. No overdraw for one half the screen and 1X overdraw for the otherhalf results in a Gpu Overdraw counter value of 50. This metric is onlyavailable when ARB_occlusion_query is available.
Objective: Because blood loss attributable to laboratory testing is the primary cause of anemia among preterm infants during the first weeks of life, we quantified blood lost attributable to phlebotomy overdraw, ie, excess that might be avoided. We hypothesized that phlebotomy overdraw in excess of that requested by the hospital laboratory was a common occurrence, that clinical factors associated with excessive phlebotomy loss would be identified, and that some of these factors are potentially correctable. DESIGN, OUTCOME MEASURES, AND ANALYSIS: Blood samples drawn for clinical purposes from neonates cared for in our 2 neonatal special care units were weighed, and selected clinical data were recorded. The latter included the test performed; the blood collection container used; the infant's location (ie, neonatal intensive care unit [NICU] and intermediate intensive care unit); the infant's weight at sampling; and the phlebotomist's level of experience, work shift, and clinical role. Data were analyzed by univariate and multivariate procedures. Phlebotomists included laboratory technicians stationed in the neonatal satellite laboratory, phlebotomists assigned to the hospital's central laboratory, and neonatal staff nurses. Phlebotomists were considered experienced if they had worked in the nursery setting for >1 year. Blood was sampled from a venous or arterial catheter or by capillary stick from a finger or heel. Blood collection containers were classified as tubes with marked fill-lines imprinted on the outside wall, tubes without fill-lines, and syringes. Infants were classified by weight into 3 groups: 2 kg. The volume of blood removed was calculated by subtracting the weight of the empty collection container from that of the container filled with blood and dividing by the specific gravity of blood, ie, 1.050 g/mL. The volume of blood withdrawn for individual laboratory tests was expressed as a percentage of the volume requested by the hospital laboratory.
Results: The mean (+/- standard error of the mean) volume of blood drawn for the 578 tests drawn exceeded that requested by the hospital laboratory by 19.0% +/- 1.8% per test. The clinical factors identified as being significantly associated with greater phlebotomy overdraw in the multiple regression model included: 1) collection in blood containers without fill-lines; 2) lighter weight infants; and 3) critically ill infants being cared for in the NICU. Because the overall R(2) of the multiple regression for these 3 clinical factors was only.24, the random factor of individual phlebotomist was added to the model. This model showed that there was a significant variation in blood overdraw among individual phlebotomists, and as a result, the overall R(2) increased to.52. An additional subset analysis involving 2 of the 3 groups of blood drawers (ie, hospital and neonatal laboratory phlebotomists) examining the effect of work shift, demonstrated that there was significantly greater overdraw for blood samples obtained during the evening shift, compared with the day shift when drawn using unmarked tubes for the group of heavier infants cared for in the NICU.
Conclusion: Significant volumes of blood loss are attributable to overdraw for laboratory testing. This occurrence likely exacerbates the anemia of prematurity and may increase the need for transfusions in some infants. Attempts should be made to correct the factors involved. Common sense suggests that blood samples drawn in tubes with fill-lines marked on the outside would more closely approximate the volumes requested than those without. Conversely, the use of unmarked tubes could lead to phlebotomy overdraw because phlebotomists may overcompensate to avoid having to redraw the sample because of an insufficient volume for analysis. We were surprised to observe that the lightest and most critically ill infants experienced the greatest blood overdraw. (ABSTRACT TRUNCATED)
For one-time debit card transactions and ATM withdrawals, banks and credit unions cannot charge you an overdraft fee unless you opt in. However, banks and credit unions are allowed to charge you overdraft fees when the bank or credit union pays a check or certain recurring electronic payments that would have overdrawn your account, even if you did not opt in.
To put things worse: a simple post-processing effect such as color grading will probably touch every single pixel at least once. This adds one level of overdraw, as it is redrawing every pixel of your screen.
In this example, I used RenderDoc to capture the same frame as the previous image. I then walk through its draw calls and analyze the overdraw they produce by switching the overlay mode to Quad Overdraw (Draw), as shown below.
It is close to zero, as the center of the sphere is exactly where the camera is.That means, that sphere will be rendered first, even though there are some objects that are likely to be drawn in front of it. And this creates overdraw by default.
Particle systems also excel at creating overdraw through transparency layers. The problem is that they often stack particles on top of each other, so the GPU has to render too many pixels in cluttered areas.
Using multisample antialiasing, many primitives, such as rounded rectangles and image elements can be antialiased and still be opaque in the scene graph. This means the renderer has an easier job when creating batches and can rely on early-z to avoid overdraw.
Setting QSG_VISUALIZE to overdraw visualizes overdraw in the renderer. Visualize all items in 3D to highlight overdraws. This mode can also be used to detect geometry outside the viewport to some extent. Opaque items are rendered with a green tint, while translucent items are rendered with a red tint. The bounding box for the viewport is rendered in blue. Opaque content is easier for the scenegraph to process and is usually faster to render.
URP performs several optimizations within a Camera, including rendering order optimizations to reduce overdraw. However, when you use a Camera Stack, you effectively define the order in which those Cameras are rendered. You must therefore be careful not to order the Cameras in a way that causes excessive overdraw.
You can use Unity's Frame Debugger, or platform-specific frame capture and debugging tools, to understand where excessive overdraw occurs in your Scene. You can then optimize your Camera Stacks accordingly.
When you do not have enough money in your account, the bank will pay or return a transaction, based on your overdraft elections. And there are also circumstances where the bank will not allow your account to be overdrawn. The bank systematically evaluates your ability to overdraft based on a variety of factors such as tenure, deposit frequency, overdraft history, bankruptcy history, etc. The bank pays overdrafts at our discretion and does not guarantee that we will always authorize and pay any type of transaction.
If Huntington does not pay your transaction and if you do not make a deposit by midnight Central Time the next business day to cover the total amount of possible return transactions and your overdrawn balance plus the additional amount needed to cover transactions that might post that day, this will result in the transaction being returned and you may incur fees from the merchant.#
If Huntington does not pay your transaction and if you do not make a deposit by midnight Central Time the next business day to cover the total amount of possible return transactions and your overdrawn balance plus the additional amount needed to cover transactions that might post that day, this will result in the transaction being returned and you may incur fees from the merchant#. 041b061a72