Presentation on theme: "A Data-driven Approach for Synthesizing High-resolution Animation of Fire Syuhei Sato Takuya Morita Yoshinori Dobashi Tsuyoshi Yamamoto Hokkaido University."— Presentation transcript:
A Data-driven Approach for Synthesizing High-resolution Animation of Fire Syuhei Sato Takuya Morita Yoshinori Dobashi Tsuyoshi Yamamoto Hokkaido University DigiPro '12DigiPro '12 Proceedings of the Digital Production Symposium
Introduction Animators try to create the desired motions by repeating fluid simulations with different parameters until a satisfactory result is obtained. – Expensive computational cost
Relative Work Control the fluid simulation to create the desired motion Covert the low resolution into high resolution Control the high resolution with low resolution Combining noise into low resolution Less realistic than those obtained by physical simulations
Motivation Similar flow pattern at different times and positions on different scales during animations of gaseous objects. Preprocessing step: database of high- resolution velocity field(2D) High resolution velocity field is synthesized from the low resolution with linear combination of the precomputed velocity field.
Features The database is created by 2D ﬂuid simulation. We use 2D velocity ﬁelds to add small-scale detail to the 3D low- resolution velocity ﬁeld. This results in a signiﬁcant reduction in computational costs for both precomputation and the run-time process. Using our synthesis method recursively, animations can ideally be synthesized with arbitrarily high resolution. The method is highly suitable for parallel computation. The low-resolution velocity ﬁeld is subdivided into small blocks and the high-resolution velocity ﬁeld can be synthesized in parallel for each block.
Database Construction Constructed by 2D fluid simulation – Divide into nb X nb blocks – Apply PCA(principal component analysis) to get PVF(principal velocity fields) Cannot synthesize detailed turbulence in 3D simulation if such turbulence is not included in 2D simulation.
Synthesizing a High-resolution 3D Velocity field A low resolution 3D fluid simulation is executed and converted into high resolution by PVF. Each output velocity is generated slice by slice and each slice is divided into blocks. – The blocks overlap in order to reduce the discontinuity.
Compute the weight for PVF Apply the above process three times: xyz – Horizontal component in 2D: u is used for horizontal components in 3D: x, y – Vertical component in 2D:v is used for vertical components in 3D: z Solve three minimization problems
Recursive Synthesis The method fails when the resolution ratio is too high. From the experience, the ratio should less than 4 Solution: vl(input) is converted to v1, then v1 is converted to v2…..