Better Renders
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An old but eloquent answer to a common question....
Displacement map (typically grey-scale) actually modifies the mesh (moves the vertices about).
Bump map (grey-scale or the red/blue one) actually a synthesis of the surface along the normal. This does not modify the mesh but influences the light as it passes along the surface.
Normal map (the "baby" blue one) also a synthesis of surface but is tri-directional. The RGB channels each correlate to an XYZ from the surface. This too does not modify the mesh but influences the light as it passes along the surface.The Bump map "costs" the least as the grey-scale image holds very little data.
The Normal map is the next cost, but will look better. This is sorta middle of the road.
The Displacement map is typically the most costly as the density of the underlying mesh needs to be high (but usually less so then the multires mesh from the sculpt).Both Bump and Normal map are rendering tricks to make thing look 3D. They render much faster because they are just tricks. Both are not generally used for large 3D features. Meaning, when you look at the object from different angle or from near on edge, you can tell it’s a fake surface feature. Bump map works best for small shallow surface imperfection, like skin texture on a face. Normal map is good for 3D feature little more larger and deeper, like wrinkle on a face.
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@unknownuser said:
You've got a very good start. Looks like you mostly just need to keep adding details.
You might continue tweaking the materials as well. The wood and flooring look overly smooth and shiny. They should probably both be less reflective and adding a bump map to the flooring will help add some more realism
-brodie
Thanks Brodie, I was thinkin the same thing about the shininess but went with it. I have no clue as to how to add a bump map! I'll have to look in to that one and see if I can find some "how to videos " to direct me in the right direction.
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@unknownuser said:
Displacement map (typically grey-scale) actually modifies the mesh (moves the vertices about).
Well thats not quite how it works.
Displacement maps were introduced by the REYES architecture ('render everything you ever saw') which was to become RenderMan (of Pixar fame). It is the microfacets created during rasterization that are moved normal to the original surface. So a displacement map on a quad for example, will result in a bumpy (self-occluding) surface even though there are only 4 vertices.
Adam
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Quite good render, As others said, you'd better add some detail.
An example are the feet of your furniture. There is always in reality some really small distance (less than 1mm) between the foot of an object and the floor, this create a small sharp shadow. You can "trick" it with a sharp edge (3DS) or simply by moving the object just 0.2 mm or 0.5 mm above the floor.
You sould also had some global illumination or some arbitrary light sources, much softer than the principal one, because in real world, the light never come from only one point.
An other point are the junction between legs and deck, you could add somme detail there.
I do not know well the bump, normal and displacement maps, but I've that they are quite powerful, take a look at it, specially for large surface with small detail like the floor.
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@adamb said:
@unknownuser said:
Displacement map (typically grey-scale) actually modifies the mesh (moves the vertices about).
Well thats not quite how it works.
That depends on who you're asking
Some engines can do microfacet/subpoly displacements, and some can not.
The render engine in LightWave will only displace real vertices (or subD'd), while other renderers (like vRay?)can make a lot more detailed displacement than the mesh density, and thus be used for making 3D grass etc. -
Thanks for the clarification, Adam (I did not know Rich is so experienced in these terms BTW).
However for us, "puny humans", there is probably not too much difference. Briefly; while bump and normal maps only affect shading (I mean just literally), displacement also affects how the mesh appears (at least). Now how this is achieved, may be a technical explanation. Good to know ("about") the finer details, too.
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@unknownuser said:
I did not know Rich is so experienced in these terms BTW
I do my homework before answering. But Adam sees through my web of intrigue.
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This Sketchup plugin works as a displacement map inside Sketchup -- it is not a render engine only feature: http://forums.sketchucation.com/viewtopic.php?p=275772#p275772
My advice, download the free Substance Player here: http://www.allegorithmic.com/products/player
this comes with several free Substances including a seamlessly tile-able wood floor generator that will create normal/bump/displacement maps (among others like diffuse and specular) based off of any wood image you give it. It's free and it's really easy to use -- try a few maps and see which results you like best...Best,
Jason. -
I've heard of this tool before somewhere? But never tried it out. Thanks for reminding me Jason
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Yes, DallasRT uses its main application to produce his mats (on the Thea forums). He shared a bunch of presets he made and that can be used for generating textures in the player. I have not used it much myself but it seems to be a nice toy actually.
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@bjornkn said:
@adamb said:
@unknownuser said:
Displacement map (typically grey-scale) actually modifies the mesh (moves the vertices about).
Well thats not quite how it works.
That depends on who you're asking
Some engines can do microfacet/subpoly displacements, and some can not.
The render engine in LightWave will only displace real vertices (or subD'd), while other renderers (like vRay?)can make a lot more detailed displacement than the mesh density, and thus be used for making 3D grass etc.LightWave Subdivision surfaces are a different thing entirely. They are fundamentally a modelling primitive (with a nice limit surface), whereas Displacement shaders are about rendering your model.
[While I admire the skill in the author of SketchUp plugins that model surface details with "real" geometry, its fundamentally not a great way of doing things. Actually modelling each blade of grass is insane on storage size - you want to be able to express the effect but have the renderer do something smart internally.]
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@adamb said:
LightWave Subdivision surfaces are a different thing entirely. They are fundamentally a modelling primitive (with a nice limit surface), whereas Displacement shaders are about rendering your model.
Yes, LWs subdivision surfaces makes subdivided polys, which the render engine handles as any other polys. The point is that while other renderers may displace vertices that are really "not there", LW (and some others?) will not. It will only displace vertices that are either in the model, or generated by the SubD engine on-the-fly. IOW it will not displace every pixel in the texture, but every vertex in the mesh. It is still very useful for many things though. -
Sorry for not getting back sooner but got a little side tracked. Although there are a lot of helpful tips and tricks from everyone this all is a bit over my head right now but will still strive to do better renders.
Thanks Kurt
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