Engineering II - Assignment 4 - Add Color Modifier and Other Constants

Assignment 4 - Add Color Modifier and Other Constants

ZIP Link

Assignment4.zip

Write-Up

The basics of this assignment were to alter the vertex shader to alter the color value across the entire object, in this case a rectangle. The default values are a gray-scale rectangle, with different gray values at each vertex.

Then we were to check for user input via the keyboard, and move the rectangle around the screen.

Finally, we were to include a generic builder (GenericBuilder) builder project, which will simplify future projects for building different assets.

Technical Write-Up

So, I was able to edit the current code and get it to draw a gray-scale rectangle correctly. The values for doing this involve editing the Material file including a section for constants. I included mine as shown below:

 I initially was going to use the g_colorModifier in a table of constants. I had trouble trying to push and pop values from the table when reading it using lua functions. I had to comment it out to get it to work. I will work on this for future iterations, as I did not provide myself with enough time to complete this assignment.

The g_colorModifier is table of values that holds an amount for the amount of red, green, and blue to be used for the pixels on the gray-scale triangle. This color modifier that is being checked for allows multiple materials to be saved with different color values. This will modify the color for the vertexShader of the item with that material being included on it. Multiple objects/entities could contain different materials, and be altered depending on their vertex shader, fragment shader, and now by constant values such as a color modifier.

Here are a couple of images showing the different colors on the rectangle.

The second step in this process was to include code that would check for user input, and update the position of the rectangle object. I started the project using the material to hold the position and velocity of the object, but this was incorrect according to our assignment. We were not to hold the position values for the object in the material. The material shouldn't worry about it's position in the world.

I did not complete this step, as I did not provide myself with enough time. I will complete this in future iterations, and here is how I will do it. I will create an Entity object which stores the position and velocity values. This entity will store a material, containing all of the information it needs to draw itself. This will include the shader paths and constants needed. The Entity will also hold a value for it's "mesh" which holds all of locations of vertices to be drawn for itself.

There will be timer and input classes to detect the player inputs, and move appropriate rates with respect to the timer. It will be checked on the Game project's update call altering the Entity's position. With this position being altered, you will have to add this offset to the vertex values, causing the object's vertices to be altered when they are drawn to the screen.

The third item we were to complete was adding in a GenericBuilder. I did not provide myself enough time to complete this section. From what I understand, this section will allow us to implement new projects for new assets quicker, with less hassle. It will allow you to copy the new asset type from the source to the target assets location. The templated generic class is used to be called in a virtual 'Build' function, to be re-written for that new builder class.

Realized Learning Moments

I didn't realize I would be stuck in the section looking for the material constants for the vertex shader. The example was well explained on the site, but I did not understand where these elements were being used in prior code.

I did not provide myself enough time to finish this assignment. I need to prepare more time for this and the future assignments.

Time Used

Reading: 2 hours
Write-Up: 0.5 hour
Technical Write-Up: 0.5 hour
Coding: 2  hours