![opengl 4.3 demo opengl 4.3 demo](https://venturebeat.com/wp-content/uploads/2018/05/2018052517075800-e7260330e4b7d47c63ff99ba9689d77c.jpg)
The renderer should use as few draw calls as possible in order to solve the problem of visibility determination.All the object-level information must stay on the GPU and the CPU should not make decisions on a per-object basis.These are the issues that motivated me in creating this demo and I established the following goals for the project: While this may work in practice, it involves too much CPU intervention even if we take advantage of conditional rendering and nevertheless, this also breaks instancing.
#Opengl 4.3 demo how to#
In traditional OpenGL the way how to solve this problem would be the use of per-object occlusion queries and rendering of bounding volumes. Also, performing the culling on the CPU would make geometry instancing barely beneficial.Īnother problem with a scene like this is that a simple per-object view frustum culling would not solve the problem completely as most of trees in the view frustum are not visible due that they are hidden by the terrain. Nevertheless, culling is a typical algorithm that can easily take advantage of the highly parallel architecture of the GPU. While that would even work in practice, it is more convenient to perform the culling on the GPU as every information needed to do it is available there. In a traditional rendering engine CPU based culling methods would be used. In order to solve this problem, the demo renders the trees using geometry instancing to minimize the number of draw calls. Also, with traditional methods the rendering of the terrain blocks and the several thousand tree models would need loads of draw calls. Due to the view distance used in the demo is quite large, several tiles of the terrain block are potentially visible on the screen and this results in a huge explosion in the number of triangles the GPU has to render.
#Opengl 4.3 demo full#
The Mountains demo renders a tiled terrain block with thousands of high detail tree models (the full detail tree model is over five thousand triangles). While this article briefly presents the demo and the used rendering techniques, the details of each individual technique will be presented in subsequent articles as the thorough examination of them needs a longer discussion that would render this article simply too long and overwhelming. The Mountains demo implements these techniques in OpenGL and further improves the technique used in AMD’s demo by unleashing the new features introduced by Shader Model 5.0 hardware and OpenGL 4.0.
#Opengl 4.3 demo series#
That demo targeted the Radeon HD4800 series and presented several practical GPU based culling algorithms implemented using DirectX10. The demo itself is mainly inspired by the March of the Froblins demo released by AMD and the SIGGRAPH 2008 Course Notes by Jeremy Shopf, Joshua Barczak, Christopher Oat and Natalya Tatarchuk presenting the actual implementation in detail.
#Opengl 4.3 demo code#
Demo binaries with full source code are also published. In this article I will present the key features of the demo that will be discussed in more detail in subsequent articles.
![opengl 4.3 demo opengl 4.3 demo](https://www.geeks3d.com/public/jegx/2020q1/geexlab-opengl-4-demopack-tessellation-demo-20200116.jpg)
The Mountains demo showcases some of these rendering techniques that, as far as I know, were never implemented so far using OpenGL.
![opengl 4.3 demo opengl 4.3 demo](https://files.codexpcgames.com/uploads/The-King-of-Fighters-XIV-Steam-Edition.jpg)
Thanks to these features nowadays more and more possibilities are available for the graphics developers to implement GPU based scene management and culling algorithms. After that, OpenGL 4.0 and the hardware supporting it even further pushed the limits of what previously seemed to be impossible. OpenGL 3.0 capable GPUs introduced a level of processing power and programming flexibility that isn’t comparable with any earlier generations. This article remains public for those who may find it useful despite its flaws. Additionally, it likely contains technical inaccuracies, opinions that the author may no longer align with, and most certainly poor use of English. DISCLAIMER: This article was migrated from the legacy personal technical blog originally hosted here, and thus may contain formatting and content differences compared to the original post.