#Ipicture 1.2 download series

Of course, transparent objects can be drawn in any pipeline, so transparent objects must therefore use forward rendering after all the opaque stuff is out of the way. This is also why with deferred rendering, MSAA is not possible. I've gathered that this far is that there is an inherent incompatibility between transparent objects, and caching surface values to a screenspace buffer (IE deferred rendering): Transparent surfaces violate the requirement that at any given pixel there is only one visible surface. Though there is one point that's kind of unclear still: I had completely forgotten about shadow cascades though which is what made it seem like it'd be easier to do than it is. We plan to look into it soon, but I'm not doing it personally so no promises.Ĭlick to expand.Thank you for the concise answer. Not rocket surgery, but just does not happen all by itself. So for transparencies to work, the shaders would need to know about the original shadow cascade render targets, and to know about the cascade matrices etc., and do that complicaded 'which cascade to sample from' and PCF filtering directly in the shader. The above does not work for transparencies though, since by now there isn't 'just a single point in the world' for each pixel on screen. Later on, in the regular objects that receive shadows, we need to only sample that single pixel from the screenspace buffer. This is the step that gathers the shadow cascades, does 5x5 PCF filtering etc. We render cascaded shadow map, and then compute 'screenspace shadow buffer' (very similar to how many other games e.g. The only real difficulty is the way we do directional light shadows at the moment. Please help me understand what the difficulty is.īut yeah, I can't for the life of me imagine what sort of technical limitation would keep Unity from having transparent objects receive shadows by now

#Ipicture 1.2 download series

I recall something similar being done by an asset, 'V-Light' - it'd draw a series of semitransparent planes in front of the light source and use percentage-closer filtering to cast soft shadows through them - which is basically the same stuff unity's lights use.īut yeah, I can't figure out what sort of technical limitation would keep Unity from having transparent objects receive shadows by now, given that it is already possible for transparent objects to be affected by cookies. In the case of a shadow map you are comparing the depth of the pixel being rendered (which can be calculated for both transparent objects and opaque objects by, for example, using the worldPos at each pixel) to the depth stored in the shadow map. Yes, sampling from a light cookie is different than sampling from a shadow map, but not in a way that should matter in this case. Spotlights, for example, can project shadow-like areas of dark and light through the use of a cookie. The latter, however? I can't for the life of me imagine what sort of technical limitation would prevent that from working simply. It'd be nice, sure, but I think I am speaking for most of us when I say we don't really care about it - the tremendous amount of work to get something like that in is probably not worth it. Keep in mind, we understand that there is a distinct difference between transparent objects being able to cast shadows and transparent objects being able to receive shadows. +1 on transparent objects being able to receive shadows. And it would complicate the hell out of rendering code, which is quite complex already. In the transparent case, the scene is rendered up to (light count * object count * constant) counts. In general shadow case, the scene is rendered up to (light count * constant) counts. In other words, performance here could be horrible. render it's shadowmap (potentially whole scene!) for each shadowed light affecting this object:Ģ.1.1. for each transparent object, furthest to closest:Ģ.1. render ambient lighting and non-shadowed objectsĢ.

step can process objects in arbitrary order everything has to happen back-to-front over the whole scene.ġ. The thing about transparency is that objects have to be rendered strictly back-to-front in order to produce correct results. Note that in 2.2 step objects are rendered in arbitrary order and the 'for each light' in 2 step also happens in arbitrary order. render ambient lighting and any non-shadowed objectsĢ.2. The long boring technical reason for this is:ġ. Transparent/Cutout shaders do cast receive shadows, because essentially they are opaque shaders, with just some pixels being 'discarded' from rendering.

Like others have said, yes, Transparent shaders don't cast or receive shadows.