A Low FPS Day

Be warned, programmer and back-end screenshots to follow. If you have a sensitive disposition, stop reading now.

My Friday began with the above shot, showing almost all the art hidden except for terrain and the new light mapped object collections.  I am currently struggling with an issue which mystery drains almost all performance from the engine when these objects gang up. The same number of regular entities with full shaders do not do this, but the new objects are playing silly buggers.

As part of my journey of experiments, and to find out where the bottleneck (or as I like to call it, squashed straw) I removed the camera cycle render loop and was pleased to see the FPS return in at just under 2000 frames per second :) Obviously very fast when you are not rendering any 3D but I have my HUDs, text and the engine running the background so it gave me hope that we could find some good gains when I started the performance work next week. 

My plan is still to finish the lightmapper and 'glass terrain' shadows but I wanted my test level to run at a decent speed, and 10 fps does not cut it. Alas I spent most of the day skipping functions to isolate the code responsible for the massive slow down but to no avail. At 4PM I decided to throw in the towel on the old school method of finding hot spots and instead broke out my new edition of the Intel VTune Amplifier XE 2015. Although this premiere tool is designed to find these kind of issues immediately, I am not too familiar with the latest version so my Friday evening has been spent learning how it works and how I can get it to work for me.

Once I can get The Escape running fast enough to run around and view lightmaps, I can revert to the Visual Camp and finish off the floor terrain shadows, small artifacts in the larger entities and squash the light mapping memory usage down as far as it will go.  Also had a few ideas how I can batch, group and consolidate the lightmap objects to reduce texture files, how to entirely skip using light map textures for very small polygon surfaces and even did some research into a way to create many instances of an object with a single draw call using a clever Vertex Shader 3.0 system of using multiple streams, one for vertex data and one for instance data.  Can't wait to get light mapping done so I can enjoy the theme park of performance optimization!