004 - Puddle Test

This was a test I conducted where the aim was trying to recreate a realistic ground surface with a puddle. It's a small scene taken directly from my storyboard where a pair of sneakers walks past our view over a puddle. I wanted to include this scene to further emphasize the gritty/rugged feeling of the street. You see the sneakers treading the ground, they're so close-up you could almost feel the grit under your own feet. It also acts as a teasing introduction to the main protagonist as you don't see him in his entirety until later in the film.

End result of puddle test

I began with numerous tests into how normal maps could be generated, especially in relation to the reflection values of materials. This I thought could be advantageous over actually 3D-modeling the ripples of a puddle (which could negatively impact polygon counts and render times). If I could also isolate the area of influence a normal map had on the puddle then I could perhaps control a ripple effect with an animated normal mapped material (looped). This was the theory anyway.

I started 'baking' the normal map data from high-poly ripple models in 3ds Max 2012. This then gave me a flat square output that I could then apply to a flat planar surface. I used Photoshop CS5 to cut a puddle shape and then mixed in a normal-mapped stone ground texture I created using Crazy Bump software. This layered with the diffuse material provided a rather satisfactory result.

However I thought it still looked quite fake. It didn't look 'wet'. I was after a more tactile feeling from this scene. Something more photo-realistic. I then looked at some more reference pictures and noticed the image was missing that slight rim of of dampness that puddles often have. Not shiny wet but very damp and dark-looking. I then added this rim to the diffuse material and really liked the effect from it.

The end result shown above is created with just one polygon. I wanted to see how far one polygon could be pushed in this test. So something that could potentially have been created with thousands of polygons can be created with just one (by using materials in a different way).



This effect was then animated over ten frames and looped to create the light rain drops in this animation.

I still think I could add more to this scene to make the rain drops more convincing. Perhaps altering the ripples and adding some 'splash back' for each drop of rain.