When an object in one table wants to refer to an object in another table, it can do so by keeping a copy of the primary key of the referred object, a concept also known as a “foreign key”.Īn example of this situation is a mesh instance keeping a reference to the mesh associated to it, and keeping a reference to the transform used to place the instance in the world. Table usually have a “primary key”, which can be used to identify each object in the table uniquely, and can also be used to efficiently lookup the object. Let’s take some time to consider how primary keys, foreign keys, and indexing apply to the design of the Scene. The design of the Scene class involves many concepts from relational database design. For example, I might want the objects in a table to be contiguous in memory, or do insertion/deletion of objects in arbitrary order, or be able to efficiently lookup an object by its name.
Opengl 4.4 scene rendering techniques update#
This allows me to use containers with the access and update patterns I need for the project I’m working on. In practice, I implement the tables of the database as C++ containers.
Opengl 4.4 scene rendering techniques code#
Later modifications to your code can be done by figuring out how your schema needs to change, which is made easier since the relationships between your objects lay bare all together in one place. Once you nail the design of the schema, the code you have to write to manage your data becomes more obvious (“I just need to hook up all this information”). I found that designing the schema of the database is a big part of the requirements gathering phase for a project. The specifics of these tables depends on your project, so if you’re doing a skeletal animation project you would also have a table of the skeletons, instances of skeletons, and so on. In a typical renderer, you might have a table of all the materials, a table of all the meshes, a table of all the instances of meshes, a table of all the cameras, and etc. Treat this class like a database: It has a bunch of tables in it, the tables contain data that possibly refer to other tables in the database, you can read/write the objects in the tables, and you can insert or erase elements from tables. The “Scene” class is very bare-bones, it contains no member functions whatsoever. In this article I’ll first talk about how I design the Scene, and then I’ll talk about how I design the Renderer. In short, the Scene stores the data to render, and the Renderer reads the Scene to render it. In my projects, the three parts of MVVM are split into two C++ classes: “Scene”, and “Renderer”. While I don’t use an actual relational database like SQL in my projects, I think the principles of relational databases are useful to reason formally about designing the model in the MVVM, so I’ll talk a bit about that in this article too.
I’ve started to notice an overall design that works pretty well for these kinds of projects, and I’m going to document it here. 8 Basic technique 2: 17 ms CPU-bound Classic uniforms for parameters VBO bind per geometry, drawcall per part, 2.Lately I’ve been writing lots of OpenGL programs for course projects and for-fun rendering side-projects.