Continuing on from the last post on general particle effects I now direct attention to the benefits of good shader application. As with last time, I’ll begin with some straightforward definitions.

Generally shaders fall into two groups, the first is vertex shaders, which directly affect existing geometry to create deformation effects within a scene. The most common use for such are applications like wave surfaces liquids, or affecting certain elements of a model for scale.

Pixel shaders, which are present in the majority of modern modelling and texturing workflows. Pixel shaders draw information from maps that present normals data, as discussed in my previous post, or the likes of opacity, height, illumination, subsurface data maps etc. Basically any information which is directly effecting the way in which a surface handles light outside of the actual geometric points.

Regarding specific shaders I’ve used in work this trimester, outside of the obvious standard normal maps. I’ve created instances for water, glowing runes and rain.

The water shader was used quite extensively in the Belisaere scene as I discussed in my previous post, as well as being re purposed as the basis for the runes moving across the charter stone in that scene, though plugged instead to the emissive colour channel, with alerternating sine and cosine

charter stone.PNG
The charter stone.

The Quiet Alley scene made use of a pretty standard setup to paint ‘moisture’ to the blue channel verts. The shader is simultaneously using a lerp function with a defaulted normal to decrease the overall normal detail of affected ‘wet’ areas to make it appear as though water is pooling in the cracks.

In the end there were a lot of points in the scene which I wanted to expand upon and just didn’t have the time to do so. The original aim was to have similar pan/rotation setup to the charter stone applied to the window spaces with visual noise to make it seem as though life was taking place inside. As I added rain to the scene at a latter stage as well my plan is also to add the raindrop shader to the floor tile, with an additional layer applied to the normal layer to show directional flow of the pooling rain towards the edge of the building. This will take place over the coming weeks as I continue to toy with the scene with the intent to add it to my portfolio.

References

Allen, B. (2016). UE4 Ocean Water Shader. Retrieved from https://www.youtube.com/watch?v=u82fxXHBFhA

Hired GunGames,. (2016). Unreal Engine 4.1.1 basic Water shader (Calm Water) Tutorial. Retrieved from https://www.youtube.com/watch?v=dpEK1APS3jM

OnlineMediaTutor | Maya modeling & animation tutorials,. (2016). What is a Shader? | Pixel and Vertex Shaders. Retrieved from https://www.youtube.com/watch?v=TDZMSozKZ20

Opara, A. (2016). Raindrops Shader Tutorial – Unreal 4. Retrieved from https://www.youtube.com/watch?v=ymAuk1z6f-g

Pulsing Emissive Color – UE4 AnswerHub. (2016). Answers.unrealengine.com. Retrieved 28 August 2016, from https://answers.unrealengine.com/questions/65309/pulsing-emissive-color.html

Technologies, U. (2016). Unity – Manual: Vertex and fragment shader examples. Docs.unity3d.com. Retrieved 28 August 2016, from https://docs.unity3d.com/Manual/SL-VertexFragmentShaderExamples.html

Water Shader Tutorial – Epic Wiki. (2016). Wiki.unrealengine.com. Retrieved 28 August 2016, from https://wiki.unrealengine.com/Water_Shader_Tutorial

 

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