Gradually lighting

There are two objects in the attachment. Both are of the same color, however one is with radiousity (Emit.). How do I make a video where one cylinder is slowly lit up (from the bottom gradually upwards)? I want to make an impression as if one object is being filled with some very bright liquid.

Attachments


Use a blend texture to control the radiosity. Map the input coordinates to an empty, and move the empty up the length of the cylinder.

Best wishes,
Matthew

Or just animate another mesh growing up, inside the cylinder, with the emit material applied to it. Make the outer cylinder glass.

Sorry, Matthew, I didn’t understand anything. I am a complete dummy in blender. Could you please write it all out to me step by step? I would appreciate it very much! What is blend texture? What is “input coordinates”? How do I map them?

How do I animate another mesh growing up? Could you please explain?

For the cylinder you want to glow:
Start with the plain material ( Emit = 0.000 )
In the ‘Texture’ panel of the materials buttons, click ‘Add New’.
Go to the Texture buttons, and under ‘Texture type’, select ‘Blend’.
Make the Blend type ‘Ease’, and in the ‘Colors’ panel, turn the Contrast up as high as it will go (staying with a linear blend and using a colourband would give more control, but I’m trying to keep things as simple as possible).
Add an Empty, and rotate it so that its X-axis is pointing downwards.
Go back to the Materials buttons for the cylinder, and in the Map Input panel, select Object and type in the name of the empty (by default, just ‘Empty’).
In the Map To panel, unselect ‘Col’ and select ‘Emit’; adjust ‘DVar’ to control the brightness of the emitted light.

If you render now, the bottom half of the cylinder should glow, but not the top half. Moving the empty up and down controls the position of the border.

Best wishes,
Matthew

Here you go, a filling cup.

Create a cylinder.
I scaled the Z of the cylinder by 2. (Press N-Key to bring up numeric input and type directly in dialog)
I scaled it’s X and Y by 0.9, thus making it smaller than the outside.
Put the cylinder in edit mode by pressing the TAB-Key.
All the verticies will be yellow and selected.
Press two keys in succession G-Key, then Z-Key. This means to grab the selection and fix it’s movement along the Z- axis (up and down). Hold down the CTRL-Key and move your mouse and you will see that is snaps along the grid. We are moving all the veritices up one grid unit then let go of the mouse button to lock that in. Press TAB-Key to exit edit mode.
What this has done is moved the center of the cylinder to the bottom of the mesh. The new scaling point will be from the bottom of the cup, not the center.

Create a timeline window and rewind.
Scale the cylinder long the Z-axis only. Type in 0.1.
Move the mouse over the 3D window and press the I-Key. Choose scale from popup window.
Move the timeline frame counter to the end of your animation.
Scale the cylinder long the Z-axis only. Type in 4.0
Move the mouse over the 3D window and press the I-Key. Choose scale from popup window.

Rewind and play your animation.

Attachments

filling_cup.blend (175 KB)

Thank you for your detailed work, Atom. I must apologise because I didn’t explain the nature of my project very well… Matthew’s approach fits better for it.

I followed step by step and hurray! That’s exactly the effect I was trying to achieve.

How do I do the same thing but with a cross shaped? The way I need to lit it up is: from the bottom to the middle, then from the middle to the right, then from the middle to the left, and finaly from the middle to the top. How do I lit it up in that precise path?

Attachments

cross shape.blend (126 KB)

Just add another texture to the material in the next slot. It can be the same texture. Then create another empty and animate it as needed. Each channel slot can have its own empty that is animated to meet your needs.

I’ve added a new Empty and played with it for a long time. But I couldn’t get texture of Right Empty to stop the emittance of the Bottom Empty. It goes right through it. Please see attached. Atom, please suggest how do I place empties to achieve this: “light cross up from the bottom to the middle, then from the middle to the right, then from the middle to the left, and finally from the middle to the top.”

Attachments

cross shape1.blend (130 KB)