A blog on software engineering by Trevor Brown

Improve the Performance of Your PC


You can improve the performance of your PC by killing unnecessary processes. Those unnecessary processes use a small amount of processing power and eat up a good portion of your memory. Just bring up the control panel and see how many processes there are. How many of these do you really need when doing resource intensive tasks like 3D rendering and gaming? Not many.

If (using windows XP) you go to: Control Panel < Administrative Tools < Services you can see a description of what each process does. Over half the processes are unnecessary for rendering and baking scenes in Blender. You can stop a process by selecting the process and clicking “Stop”. By stopping the processes you don’t need you can speed up your render time by three or 4 percent. That might not seem like a big improvement, but when rendering takes three or four hours, it is definitely worth it.

Ok, now you have started to stop processes by manually clicking stop for every process. This is a pain! If you double click on the process in the Services window, a dialog comes up with several options. There is a drop down box with the startup type options. You can set the process startup to automatic or manual. By setting the process startup type to manual the process will not start unless you start it manually. This is fine if you are never going to need the process. But some processes you need to use most of the time and only need to turn off for resource intensive tasks(processes like your anti-virus program), so these you will still need to manually start and stop in the Services window.

So I will show you a better way to manage your processes.

You can create a MS-DOS Batch file to stop all the processes you don’t need. You can also create a Batch file to start them again once you’re finished rendering. Creating a Batch file is easy. First, get the name of all the processes you don’t need (use the name at the top of general tab in the properties dialog, not the name of the process in Services window). You can find a list of all the unnecessary processes at, check it out. There are dozens of processes you think you need but don’t. You could even stop the Explorer process while rendering or gaming! (I would not recommend it, but you could). To now create the MS-DOS batch file, right click on your desktop and create a new text file. Rename it to StopProcesses.bat. Now right click on it and click edit. In notepad write the following line of code for each process you want to stop (_processname _being the name of the process you want to stop) :

net stop _processname_

Add a new line of code for each process, then save the file. Now when you run the file it will stop all the processes you don’t need! You can also create another file to start the processes again. Just type this line of code for each process you want to start.

net start _processname_

You now can stop and start all the processes you don’t need by just running a batch file!

Note: I learned this from an IT guy. I am not an IT guy so if you see anything that is not completely accurate or incorrect please let me know. I am using XP so I am not sure how this works on Vista or Windows 7.

Blender Calculator

Here is a secret Blender feature. A calculator. No, there is no calculator window and no, I am not talking about the Interactive Python Console. This secret Blender feature can be found in every numeric input box and every slider button. Every input box can solve arithmetic problems just by entering in the equation and pressing enter. Simply click on the box and enter a problem like .8/3 and press enter.

This may seem like a worthless feature. A calculator? Why would I need that? If you have never used this feature it may seem pointless. However, this feature can dramatically speed up your workflow and once you have used this feature you won’t be able to live with out it! Here’s an example.

Say you are working with a material with a reflection value of .941 and you figure it is about one-tenth too reflective. Now you can guess a value. Somewhere ‘round .85, right? Or you can use the calculator. All you do is just left click on the slider, and then to the right of the number left click and enter the multiplication symbol * and then enter .9 and press enter. That’s it! You have now just lowered the reflection value by exactly 10%.


It can even solve algebraic equations like this: (I have no clue why you would need to do this.)

Algebra equation in inputbox

The Blender “calculator” will always round it’s answer to the nearest one-thousandth (unless your dealing with an integer value like the frame number, in which case it will be rounded to the nearest integer) and the results will not exceed the minimum and maximum values of the input box. Usually 1 is the maximum value and 0 is the minimum ( in some case there are no min’ and max’ values).

Hopefully, you can see the advantages to using mathematical operators in Blender’s “calculator” to perform quick, accurate changes to the value of a parameter. Once you get use to it, it will save a significant amount of time and greatly speed up your workflow. It eliminates the need of a calculator for complex problems.

Premutliplied Alpha in GIMP

Watch Premulitplied Alpha in GIMP
This tutorial is 3.5 minutes long.

If you have ever rendered an image in Blender and decided to do the final composition in GIMP you may have discovered that when you placed your foreground layer over the background layer a nice fuzzy black line (fringe) appeared around the edges of your foreground objects. This is because you were using premultiplied alpha in Blender. GIMP does not have a way to handle premultiplied alpha and it causes the foreground layer to have fringe around the edges. I have spent hours trying to get rid of black fringe on images with premultiplied alpha in GIMP. In this tutorial I will share a solution of removing the fringe caused by premultiplied alpha.

Here I have the foreground image with a white monkey on a transparent premultiplied alpha background and a white background image.

foreground_layer background layer

First load both the foreground and background layers into GIMP, making sure the background layer is on the bottom. You can see here the black fringe clearly visible against the white background.

fringe closeup

Now hide the background layer and view the channels. Select the alpha channel and drag it down to the box below. You now should have a copy of the alpha channel. Before you do the next step switch the background and the foreground colors so that the background color is black, as shown.

background and foreground colors

In the layer tab, right click on the foreground layer and click “Remove Alpha Channel”. Now add a layer between the background and the foreground layers and fill it with black. Now right click on the middle layer and select “Add Layer Mask”. A dialog will come up with several different masking options, choose “Channel” and select the layer we just copied from the drop-down menu. Now make all the layers visible. Select the foreground layer and set the blending mode to “Add”. Your setup should look like this.

final layer setup

Now you will still probably have some fringe, so click on the middle layer’s mask and use the Curves tool to remove the fringe. Click on center of the curve and pull it down some until you don’t see any fringe. If you pull it down too far you will see white fringe.

curve setting

That’s It! you should now have a fringe free white foreground on a white background!

fringe free border