Sophie went out on Sunday to take some test photos of a ball ball on a pavement to test the ball lighting technique and see it if is a viable option to go on to develop a work-flow when lighting each scene. Sophie asked what I thought and if I thought that they were too washed out. At this stage, I still didn’t really understand the technique nor what to look for. So my response was to use a reflective ball ball next time so that we can make a HDR image because Image Based Lighting is another technique we can use to light these scenes. It may also provide me with better lighting information, but again, I am not too sure what to look for. Here is one of the images that she took:
Light Test #1.
Due to the fact that compositing is not an area that I have researched thoroughly, I wasn’t confident in what I was meant to do with regards to setting up a plane for the shadows. The Physical Sun and Sky method was proving too complicated for what I wanted to do, especially when the image plane was causing interference with the lighting, I decided to stop there. So I decided to light the shot manually with Maya lights.
So I setup a 3 point light system in Maya (See image below) and plugged an image through a camera in Maya (select camera. View> Image Plane> import image). Upon reflection this method would have been the one to use when using the physical sun and sky option as apposed to creating a planar and applying an image sequence as a texture…something I should definitely bare in mind for the next light test.
During this lighting test, I have begun to understand more why the ball lighting technique is used, it’s used as a reference object in the scene, you can use it to see if there are any caustics that would be involved because I was asking myself this when I was lighting these scene, further more light direction, shadow direction, length and detail.
One of the main issues that I’ve come across in this test are shadows not coming up in the render. I turned off each light to see if any of the lights were overriding the key light, no result. I turned Maya on and off to see if it just needed resetting still no result. I have checked the render globals, ensured Raytracing is set as the renderer, I have increased the shadow samples as well. When this did not work I changed from raytrace shadows to depth map to see if that would make a difference, but this did not work.
Issues that have been sorted are attaching an image/image sequence through the camera as apposed to using a planar (this causes a shadow overcast on the object) and secondly not so much an issue, but a positive outcome from this test; I have a better understanding of why ball lighting is used. An issue that hasn’t been resolved as of yet are the shadows, this will be something that I will continue to test through trial and error and I would not be surprised if it was something simple.
What I have also researched for lighting and rendering for the Raven project, I would need to create a shadow light, so a light dedicated to just emitting shadows- so this would go on a separate layer. In addition a beauty pass, occlusion specular, highlights and maybe a lighting pass (I am referencing a book called: [Digital] Lighting and Rendering by Jeremy Birn).
With most of these renders, they can be done in one go using the render pass system which is quicker because it renders the image sequence but at the same time it breaks each image down in to those passes that you specify without incurring any additional render time. The occlusion will probably have to be rendered on a separate layer.