Do lightmaps actually work?
by Jacob Dankovchik · in Torque 3D Professional · 10/11/2011 (11:27 pm) · 6 replies
I appear to be having issues with lightmap texture layers. I have a working second UV channel, all other advanced layers function without issue. However once I apply anything as a lightmap, the entire model simply turns completely grey.
I decided to take a look at the Burg mission example to compare and see if I could pinpoint an issue from that, until I noticed that the entire mission makes no use of the lightmap layer, all of the "lightmaps" are in the form of a tone map instead.
So do lightmaps not actually work? And yes, it matters. I don't want to use a tonemap because:
1. It does not have a full effect without HDR in use, which I do not want to use.
2. It does not project shadows on to your model like a lightmap would. Take notice of the player as you run around the Burg level; you are completely unaffected by shadows.
If this doesn't work, is there any actual plan to fix this? Or is it something I'm doing incorrectly?
I decided to take a look at the Burg mission example to compare and see if I could pinpoint an issue from that, until I noticed that the entire mission makes no use of the lightmap layer, all of the "lightmaps" are in the form of a tone map instead.
So do lightmaps not actually work? And yes, it matters. I don't want to use a tonemap because:
1. It does not have a full effect without HDR in use, which I do not want to use.
2. It does not project shadows on to your model like a lightmap would. Take notice of the player as you run around the Burg level; you are completely unaffected by shadows.
If this doesn't work, is there any actual plan to fix this? Or is it something I'm doing incorrectly?
About the author
#2
They just add fake shadows to mesh - tonemaps add coloured shadows to the mesh.
10/12/2011 (9:16 am)
Quote:That's not what lightmaps do.
no actual shadows cast from it onto the player or anything
They just add fake shadows to mesh - tonemaps add coloured shadows to the mesh.
#3
On top of that, as I just tested, the lightmap can be colored as well. It appears to do the same thing as the tonemap except just break normal maps.
10/12/2011 (10:15 am)
Well, perhaps we should make the rest of the game and graphics industry aware that what they call a lightmap isn't actually a lightmap then...On top of that, as I just tested, the lightmap can be colored as well. It appears to do the same thing as the tonemap except just break normal maps.
#4
10/12/2011 (11:46 am)
You may want to re-ask the game and graphics industry about those terms you're using.
#5
10/12/2011 (11:51 am)
Quote:It is tempting to assume that lightmaps emitt light - they don't. They are used to burn light and dark regions on to textures.
2. It does not project shadows on to your model like a lightmap would. Take notice of the player as you run around the Burg level; you are completely unaffected by shadows.
#6
Tonemaps are used to smoothly approximate a high dynamic tonal range (usually represented by 32-bit floating point color components) on displays with limited dynamic range (usually 8-bit color components). I haven't actually used tonemaps in Torque3D so maybe they use them in some other way, but that's their general purpose.
10/12/2011 (12:01 pm)
Lightmaps are statically baked lighting information. They're usually grayscale to reduce memory footprint, but they can be colored too. They generally do not hold information to cast shadows on dynamic objects like players, though they can be combined with shadow buffers to produce a combined lighting effect. The dynamic shadows will usually be of a lower quality than the baked lightmaps. You can sometimes store some limited information for things like sunlight shadowing, and some game engines will just sample the shadows around a player's feet to fake it a bit, but that's about it.Tonemaps are used to smoothly approximate a high dynamic tonal range (usually represented by 32-bit floating point color components) on displays with limited dynamic range (usually 8-bit color components). I haven't actually used tonemaps in Torque3D so maybe they use them in some other way, but that's their general purpose.
Torque 3D Owner Jacob Dankovchik
So basically it's just a tonemap that disables normal maps? Or am I still missing something? A little bit of information on this would be most helpful.