WIP: Metaballs

[MartinBuessemeyer]

Current setup:

The demo is rendered by drawing a NDC-Triangle. The whole geometry is loaded via textures.

Features:

• Multiple Metaballs that can interact with each other
• Phong shading with point lights
• (possible but currently not used) Metaballs with negative energy
• skybox though the texture access vector is wrong / broken.

TODO:

• raymarch with newton
• freslen-term (- image-based-lightning)
• add metaball surface

Further improvement:

• even faster raymarch
• transparent metaballs (current version is too basic)
• metaballs have individual alpha value

FAILED to implement so far:

• I tried to add a camera to the scene but ended up seeing nothing.

Open questions:

• When two metaballs are merging, the normals of the metaballs point in the opposite directions thus leading to a normal that ist almost near 0 which leads to rendering artifacts at the merging point.

[coveralls]

Coverage remained the same at 20.208% when pulling 650eb23203c716adca9cdfe66036f076efd0be51 on metaballs into f799c52a38ccc998d097b7224e1d220713d51b53 on master.

[cgcostume]

its too slow for now 🥲 - probably going to optimize at some point. We will keep the branch though! Thanks a lot.

[MartinBuessemeyer]

That matches with my memory. I did not see further performance improvements when using the newton method. I would suggest switching back to the interval bisection. As far as I remember, it took more iterations, but each iteration was way faster and was therefore overall faster. And it did not have the small rendering artifacts (as far as I remember, at least).