Off-piste simulator: Part 3

Time for one more step in this snowy experiment. I can’t help feeling like I’m dropped of the wagon right now with all kick-ass 3D demos around for the upcoming flash 3D API molehill. Of course, it’s not just about the amount of triangles, but also the creativity and love put into those you got. Anyway, I hope that you will like this piece while we all waiting for the salvation. Just put a smooth-modifier in your mental stack.

To mention some of the additions to this version, I have added collada-animations, a background view, different camera-angles including the typical fish-eye lens seen in many snowboard-videos. But the main feature is that you now can control it and make nice bezier curves in the snow yourself. You have three different inputs to play with:

Steer with the arrow-keys. Press down-arrow to bend your knees and push the snow a little harder. With this input-method it’s simple to keep a continuous pace, but it feels a little static.

In my opinion a more dynamic way to get smoother turns and more control. Until you found your pace it can look a little funny, because the engine need a previous turn to calculate the leaning angle. Try to move the mouse back and fourth as an arc across the slope to get a balance of speed and pressure, simulating the g-force when surfing through the snow.

This is quite fun to play with. I like the idea of moving your own body to control the movement. The face-detection-algorithm steals some CPU, so it’s maybe not the best choice. Use the same technique as with the mouse. Y-axis controls the pressure. Calibrate yourself against the webcam preview image to find a good position.

Now, lets make some turns.

Alternative controls

I don’t have a multi-touch trackpad, otherwise that would have been cool to control each foot with a finger, like a finger board. Or a wacom-board, with different levels of pressure.

Would be even cooler to control the board in 3D. Or maybe connect a wii-control to it?


To get a natural and correct looking turn, the character have to lean the body through to whole turn, almost before the turn even starting. So how do we know which phase of the turn we’re in? We could “record” the position and interploate and adjust it afterwards, like a bezier-drawing application. But I do not want this delay as it’s affect the response and feeling of riding in real-time. I came up with a different approach. I have two markers, xMin and xMax. Each time a the turn reach it’s maximum or minimum position the values are updated. I then have an estimated range of the next turn (if I assume that the next turn will be the same length). The current x-position is then compared with the estimate range and I got a normalized value between 0-1. Now I can ease that value with a Sine.easeInOut-function. That eased value is then used for the leaning angle. If you do a shorter or longer turn than expected it will of course look different, or before you find your pace, but it is still looking ok.

That’s all for now. Thanks for reading!

Off-piste simulator: Part 2

I have some  improvements for you since last time!  New stuff in this version is terrain, a rider and some snow-particles. In this demo, try to combine different values to see how the rider and the snow is affected. All parameters is connected together, so you can get pretty cool results.

Launch demo

I mentioned that I could add effects to each layer in the heightmap/texture-comp. I now added perlin noise to the base-layer. The offset for each octave is the same as the track-layer-scroll so they are in sync with each other.  By resizing the y-scale of the noise the terrain got more stretched look, like ridges, or dunes, created by the wind. It’s a simple example of distortion and more parameters and effects will be added to create different slopes. I also read out the height-value at the snowboarders position. Notice how the rider floats on top of the terrain minus the snow-depth and depending on the current pressure.

The rider
The guy is a fully rigged model imported from 3d studio max. I have just begun to test the bone-support in Away3D, that is way he is looking like a rookie. For now I just control joint rotations, but later on I will try to add bones-animations and poses, especially if I add  jumps and tricks. I tried to move the joints up and down, but I could not sort that out with correct IK and without destroying the mesh. I’m sure that method would be pretty CPU-intensive as well with all the recursive translations going on in IK. I have to dig deeper into that later.

Just for the record, I’m in fact a skier, so maybe the movements are completely wrong since I never even tried a snowboard :)

I also added some snow-particles, or animated sprites to be more specific. The animation is dynamic depending on the speed and the pressure. If more pressure and the snow is deep, the particle will fly longer.

I guess next time I will try to make the rider controllable.

Off-piste simulator: Tracks

The winter is just around the corner. If you, as myself, enjoying alpine winter sports, this little toy will get you into the mood. Imagine that you have climbed all the way up the mountain, before the lifts starts feeding the mountain with people. You want to be sure that you get a ride on fresh untouched snow all the way down. You now standing on the top and watching the sun rise behind a nearby peak. Googles on. Gears on the back. It’s you and the mountain… I love that feeling!

This is the first part of this experiment of making a off-piste simulator/game in Away3D. The first step is to create the slope and generate tracks in the snow. Check it out the first test

I got inspired by @tonylukasavage and his morphing mesh experiments with HeightMapModifier in Away3D.

Some notes about the texture; I start of with a bitmap filled with the color-value 0×80000. That fill represents the center of the offset. I then draw the track to another BitmapData ranging from black to red. To make the scrolling effect I found a method that I’m never used before: BitmapData.scroll(x,y). The two layers is comped together to a single bitmap. One advantage of using layers is that I can add noise, shadows and other effects to each layer. The heightmap is then converted to a normalmap with NormalMapUtil and a texture with paletteMap. Now I got what I need to create a nice phong-shaded Pixelbender material. The grid has very few triangles (25×25 segments), I have to save some cpu for the character and the other stuff. I’m not doing any real-time triangulations either, so in some cases the vertices starts to jump around. I have to accept that for now.

I don’t really know the outcome of all the future parts yet, but next up is to add a character and some controls.


There have been a lot of things to deal with lately so I have kept a low profile online. But last night I finally did a little experiment. It’s a little toy to make models made of cubes in away3d. Or infact, there is just ordinary planes. I suspect that it should be much faster if I created the geometry inside i single object, but this was fast enough for this experiment.

The material of choice is a WhiteShadingBitmapMaterial. The shadows are baked into the bitmap depending on the surrounding nodes. To render the shadow I use fillRect-method on the BitmapData. To make the shadows more soft I use the diffuse-color, but with lower brightness. When all shadow-rectangles are drawn the bitmap is blurred with applyFilter. The shadows was added to get a kind of fake ambient occlusion. Each cube, or node, has it’s own position in a 3d-grid (multidimensional array). When a plane is clicked a new node and its corresponding planes is created, animated and evaluated. If there is any doublets or planes inside the structure, it’s removed.

Click on the some of the models for a closeup view. Or just try it out yourself: Extrude the cube, dude!


I have been a huge fan of voxels and voxel-engines lately. I know it’s pretty big and few voxels, but let me call this a micro-voxel-editor please ;-)