- Visual studio sfml texture load image code#
- Visual studio sfml texture load image series#
- Visual studio sfml texture load image windows#
As the only parts of the sprite I wanted to appear reflective were the vehicle's windows I drew the alpha channel by hand. This is convenient because the normal map relies only on the RGB channels to represent XYZ pixel coordinates so the alpha channel of a 32bit map can contain, in this case, reflection values (it is not uncommon to store other data such as transparency in the alpha channel of an image). Modulating the reflection map onto the sprite is then done using the information stored in the normal map's alpha channel. The most important thing about the reflection texture is that its coordinates have to be offset relative to the position of the sprite in texture coordinates, so that the reflection map appears to stay still relative to the sprite's motion. The reflection map is an image of some clouds which offer a vague representation of the sky and is passed to the shader via another uniform sampler2D variable. You may have also noticed in the video that I didn't just stop at normal mapping - I took the procedural idea one step further by adding a reflection map to the demo and extended the shader to draw it on the sprite (I have further plans along this line, hence the unfinished shader). Here's the demo in action:Īs you can see the shadows cast on the sprite move realistically as the light and the sprite move around the screen, an effect I am personally very pleased with. I won't include the shader specific stuff here as it's not complete, but there are plenty of resources to get you started on your own. tParameter("light", sf::Vector3f(sf::Mouse::getPosition(renderWindow).x, 600.f - sf::Mouse::getPosition(renderWindow).y, 0.04f)) Shader.loadFromFile("ag", sf::Shader::Fragment) Sf::Sprite sprite = sf::Sprite(colourMap) NormalMap.loadFromFile("car_normal.png") Sf::RenderWindow renderWindow(sf::VideoMode(800, 600), "Normal maps, yo") Set the shader light position to the mouse cursorĭraw the sprite to the window buffer via the shader Set the shader normal map parameter to the normal texture
Visual studio sfml texture load image code#
Using SFML it takes no more than a few lines of code to produce a demo: This was enough to try rendering the sprite. There is some slight artifacting on the 'roof' of the car, but once the sprite is scaled down it's not noticeable. To test my theory I first drew up a basic mesh to represent the body of a car as viewed from a top down perspective, common to many 2D racing games. As the sprites were 3D models anyway all I needed to do is render some of the 3D data to bitmaps which could be used for procedural mapping. Assuming I had light data within my scene I ought to be able to add some depth to my sprites using this technique. These maps are used to modulate the coordinates of texture pixels in 3D space so that any lights within a scene will create reflections and shadows on the material providing much more detail, usually without having to increase the complexity of the underlying mesh. It occurred to me that this can be improved upon by using a normal map. The problem with this approach is that the 3D effect is spoiled when it doesn't react in real time to the lighting around it.
Visual studio sfml texture load image series#
While developing Threat Level I made most of the sprites by rendering 3D models to a series of stills to create 2D sprite animations. This includes procedural mapping, the possibilities of which I have been exploring, in this case centering specifically on normal and reflection mapping. This essentially means a sprite is effectively a flat model which can take advantage of programmable shaders like any other 3D mesh. The 2D effect is achieved with a single quad mesh mapped with a texture the size of the viewport, on to which smaller quads/textures representing sprites are rendered. Modern hardware accelerated APIs such as SFML are aimed at creating 2D games and applications but, by their hardware accelerated (in SFML's case OpenGL) nature, are actually 3 dimensional. This is a bit of a generalisation, of course, games such as Dota2 employ quite a complex set of maps to create its materials, for example, and high-end rendering packages such as V-Ray are far more complex. Most commonly these materials are composed of a coloured texture which provides the basic detail of a model, a normal map which is used by a pixel/fragment shader to provide pixel-level detail, and other information such as pixel reflectivity or transparency, usually stored in a single channel of a texture map such as the alpha channel. Procedural mapping is a technique applied to 3D models, both in real time games and pre-rendered images, whereby several texture maps are used to build up a particular material. Recently I've extended this line of thought by applying procedural mapping techniques, usually found in 3D games, to 2D sprites in real time. In a previous post I touched on using post process shaders to fake a common 3D effect ambient occlusion.
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