>SDF is still just a surface/boundary representation
Meshes and Bezier patches are parametric representations (defined over R^2, evaluated with vec2, output vec3). Implicit functions are volumetric representations of surfaces (defined over R^3, evaluated with vec3, output float). This is a key difference between parametric modelers like AutoCad and implicit modelers like nTopology.
>density grid instead of a SDF if you're dealing with anything volumetric, such as clouds or smoke.
These functions of time change every frame. In the implicit paradigm, it's not necessary to evaluate the smoke ahead of time since sphere tracing can reduce to marching adaptively when we are within smoke. Image quality will not be bound to any resource resolution other than the screen (a low res smoke grid would appear blocky).
I agree with you that the current triangle-based RT implementations have faster alternatives that accomplish similar things on the surface.
Meshes and Bezier patches are parametric representations (defined over R^2, evaluated with vec2, output vec3). Implicit functions are volumetric representations of surfaces (defined over R^3, evaluated with vec3, output float). This is a key difference between parametric modelers like AutoCad and implicit modelers like nTopology.
>density grid instead of a SDF if you're dealing with anything volumetric, such as clouds or smoke.
These functions of time change every frame. In the implicit paradigm, it's not necessary to evaluate the smoke ahead of time since sphere tracing can reduce to marching adaptively when we are within smoke. Image quality will not be bound to any resource resolution other than the screen (a low res smoke grid would appear blocky).
I agree with you that the current triangle-based RT implementations have faster alternatives that accomplish similar things on the surface.
Thanks for the links!