How can I fine tune these shadows

Support Lighting and Rendering
#1

I have 2 images here. The 2nd has a single plane with emission which casts a soft shadow. The 1st image has an added sun lamp with a size 0 casting a sharp shadow.

I would like to only have the shadow from the lamp. How can I set this up? Also, I had to set the lamp light to 0.200 because at 1.0 it was too bright and it interfered with the scene. Is there a simple way to make the lamp cast a sharp shadow without brightening the scene?

I’m familiar with nodes but I have very little knowledge of them right now. So to summarize, I want to make sure that only one light source casts a shadow (a lamp) and other light sources (emissions) illuminate the scene, but don’t cast shadows. I’m using Cycles.

Here are the 2 images

Attachments

pic_1.png720×486 186 KB

pic_2.png720×486 234 KB

#2

if you just want to brighten a scene without shadows just use environment lighting.

#3

Not just the scene, but better control of the shadows. I need a very dark and sharp shadow of the table, without washing out the rest of the scene.

#4

wineandcheese-
m9 is spot on- that’s what you want to do for easily bringing up the lighting intensity of your scene. For better control of shadows, I’m partial to the area lamp in cycles. Bigger lamp=more diffuse shadows. Smaller lamp= tight, crisp shadows. Just play with the scale of the lamp a bit. You’ll find your sweet spot.

#5

Here is a Sun light set to a Size of 0.001. NOTE: You only get this option with actual Lamp objects. Emission based meshes do not have this feature.

Attachments


#6

Use suggestions as listed above.
With your preferences try setting the sun to not cast shadows (+ add env.lighting), then add a lamp enabling “only shadows” (spot, sun, point, whatever). This should give you enough option for finetuning since the lighting and shadow are separate.

#7

Alright, I tried a few different ways and it works out so far, but I don’t have fine control so I have other problems. The last recommendation was to set the Lamp to shadows only, but this is not available in Cycles, only in BI. Is there a way to do this with Nodes? If yes, could someone give an example of how I would do this?

Also, other problems I have, that are not part of the initial question, but related to lighting is color bleeding. I might have a pink floor and a white ceiling, and as soon as it’s rendered, the ceiling is pink also. Setting Diffuse, Shadow and Transmission for the object, on and off does not make a difference, so I have been playing with the lighting. No success yet with the settings. Here is another image. Note, that in this image, there is no ceiling. I have 3 planes set to emission from above the room and 1 Sun Lamp with a low intensity to cast the sharp shadow. Overall, I have really good illumination, but slight adjustments in lighting that are necessary when adding objects, can really make the intensity too high. I don’t want to fixt that with a post process. It has to work with the intitial render. If I add a ceiling to this scene and point the camera up, the ceiling object has to be set to Shadow off, to allow the planes above to light through. I have all kinds of light collision problems. So this is turning into a second question, but if someone has input on this, I would appreciate it.

Attachments

Scene_1.jpg1920×1080 290 KB

#8

If you try to ‘trick’ lighting you will end up with un-natural looking scenes. For instance, the ceiling in my house is painted white. When I turn on the light in the morning, it looks kind of yellow due to the type of bulb I have in the lamp on my table. This is the way light works. So if you don’t want a pink ceiling in your scene remove the pink floor.

“Less not more” - The Residents