# Blender Notes: Donut Tutorials

## from parts 1 uwu 7
- add object, options for object right after add... these options will disappear once you click off the object. temporarily bring these options back with f9
- Subdivision Surface Modifier -- getes rid of jagged edges in round shapes.
- doubles detail on entire mesh
- tab goes into edit mode
- duplicate, then use the "P" hotkey to make the duplication its own object
- "P" is the hotkey, then we would use "separate" to complete the object separation
- add thickness to icing of donut
- use the "Solidfy" modifier
- creating droppy icing
- proportional editing duplicated layer downwards
- to prevent clipping we need to snap object to mesh underneath
- use snapping tool, magnet icon in top center
- ctrl is temporarily enabling snapping as well
- "snap to face" is what we want to use for icing dropping
- "project to individual elements" box will also snap extra droops
- extruding droopy parts using "E" to extend some points
- shrinkwrap modifier -- snaps to chosen mesh
- sculpting
- draw, inflate, and smooth are most commonly used
- image renders
- ctrl + alt + num pad 0 will snap camera to current view
- N to bring up properties -- under view, click camera to view
- top right corner to "rendered viewport" will give us render vision live in viewport 
- cycles and evvee are two main render engines used
- Evvee is a real time rendering engine --
- in evvee undersettings, we want to edit cube size under shadows -- we want to pump up this setting a lot
- cycles -- offline rendering engine. calculates light bounces (evee does not do this

- adding materials
- with object selected, go to materials tab in bottom right, then add new material 
- roughness --> sets the glossiness of an item (glossy is the invert of rough)
- how freshly iced do we want donut to look?
- subsurface scattering for light effects where light is going through something and "diffusing" 
- Texturing and Shading the donut
- we dont want donut to have one solid shade. real donuts are spotted and textured in different spots and batches
- node editor access through shader tab at the top 
- node editor is a copy of the materials tab
- texturing and combination of things and doing more interesting stuff should be done with node editor
- nodes work from left to right 
- add new nodes 
- nodes are going for painting things in that can be easily changed later -- for non destructive texturing
- noise texture and image texture are most common
- add --> converter --> color ramp to texture colors 
- enable node wrangler to preview direct from one node to another using (ctrl + shift + left click any node = preview just that node) 
- add image texture node in order to add images to objects
- NODE INPUT OUT PUT COLORS -- in general you want them to match
- texture coordinate node will help with texture stretching, helps with mapping 
- 1 node output can go into changing two aspects of the shader 
- screenshot above we are editing the "bumpiness" of the donut by taking the noise texture node and inputting into the "normal" input on object
- normal is directions on face of the model -- doing something to "the normals" of the object, you are changing the appearance of the way those faces look / are
- add node: vector: bump -- output noise into height input 
- do not change strength, should always be 1. changing distance is what we want to change how far bumps are. distance value in blender units (default metric)
- .002 distance value for organic donut type of bumps
- less detail is better -- the more detail used, the more detail everything else needs

## fom parts 8
- texture painting
- switch to texture painting tab 
- add image texture and remove color painting (for this example of donut) 
- hit new on image texture and adjust values 
- back into texture paint mode 
- change texture paint color -- now when you paint on to the object on the right side in 3d, the 2d texture on the left side will reflect that painting 
- this is funny tweet uwu 
- when in texture paint, notice the star next to image 
- this star means that the texture painting has not yet been saved to the object ... it is only temporarily visible in temporary blender session

## episode 9
### fun with geometry nodes, yay
- beginner geometry nodes through adding sprinkles to a donut
- we are going to select icing (where we want to put sprinkles)
- from there we want to access geometry nodes which can be done several ways
- one way is to split screen and choose geometry node editor in the menu pointed to here 
- another way is to just go into geometry nodes tab at the top 
- get rid of top left panel by merging screen and click new to make a new geometry node ... also notice new modifer in stack to the right for the geometry nodes 
- to get sprinkles, we are going to: add --> point --> distribute point on faces 
- notice the icing is now gone from the previous screen shot -- that is because the distribute points node has converted the icing into the points that have been distributed. in order to solve this we are going to add: geometry --> join geometry node as follows, and the icing will re appear 
- create cylinder object and scale it so its roughly the size of a sprinkle; be sure to not have that many faces on it 
- now we are going to add: instances --> instances on points as a node between "distribute points on face" and "join geometry" 
- drag the sprinkle object from the top right window into the geometry nodes panel, then input gemoetry into instance on points 
- adjust density, plug rotation into rotation, make it go brrr until good 
- for more organic sprinkles we are going to add: utilities --> rotate euler node in between all these nodes ... edit values 
- introduce randomness to the sprinkles: add "random value" node, plug value output into rotate euler "rotate by" input; adjust rotate euler node to local; play with values in random value node 
- how to stop sprinkles from appearing in places we don't want it? e.g. appearing on droopy parts of the icing, and underneath the icing mesh as well -- we need to weight paint for this.
- weight paint will auto add vertex group. value in btwn 0 and 1 for each point on mesh. we paint this value in vertex by vertex.
- select icing mesh then hit control tab to bring up menu and select weight paint 
- disable view of geometry nodes modifier by pressing button 
- in weight painting dark blue is 0, red is 1, and other numbers lead up to 10 
- we want to use weight painting to control where the sprinkles are going to go 
- go back into object mode after weight painting
- how do we use weight paint in our density? we plug our geometry nodes into the group input's blank slot (will auto gen a new blank spot) 
- side note the density of the geometry nodes can be edited here just the same as if you were editing them in the actual node screen itself 
- weight painting assigns values 0 to 1 on the icing so we will need to put in a math node set to multiply in order to scale the density better 
- how do we stop sprinkle clipping? previously with particle nodes we could not prevent this, could only play with seed value to fix things.
- on "distribute points on faces" change random to "poisson disk" 
- play with values till gud 
- the next part will improve the sprinkles more by introducing random variations to each sprinkle as well as giving each sprinkle a randomly generated color

## part 10 of the DoNuT
- first thing we want to do here is get the sprinkles to be randomized and look more like sprinkles
- select the sprinkle that is being used by geometry nodes and distributed around the icing object and apply subdivision modifier to it 
- this will make the sprinkle appear to be slightly pinched so we are going to add a "Loop cut" (?) to it -- in edit mode we are going to hit "Ctrl + R" on the sprinkle and then drag from center to each end (once for each end of the sprinkle) to make it look more like a sprinkle 
- right click sprinkle and click shade smooth 
- now we are going to add spinkle variations -- first duplciate the sprinkle 
- enter wireframe mode with the duplicated sprinkle in edit mode with vertex selected next to edit 
- scale it to be a little longer and different shape than the original 
- repeat the process to make a third sprinkle. now we have one original, one longer, and one shorter 
- now we are going to duplicate a fourth to make a squigly sprinkle. it is the same process except instead of one loop cut with ctrl + R we are using the mouse wheel to add two loop cuts with ctrl + R 
- now to bend the sprinkle we will select the face vertexes on one side, rotate them, then do the same on the opposite side -- make sure to not select the points in the middle from the loop cuts 
- duplicate curved sprinkle to make a second curved sprinkle 
- now that we have our five different sprinkles, we need to make the icing on the donut populate with all of them, not ust the one original sprinkle. in order to do that we go into our nodes and change "Object Info" which takes the original sprinkle and distributes it on the icing and replace it with "Collection Info" 
- must select all 5 sprinkles and move them into a collection. with all five selected hit "M" and then select new collection 
- drag and drop sprinkles into node screen and plug it in to "instance" for the "instance on points" node connected to the icing 
- at first it will appear all weird and janky but there are some buttons to press on the nodes that will fix this 
- clicking the check boxes for "pick instance" and "separate children" and "reset children" will fix the janked out appearance 
- now we want to assign random colors to the sprinkles. select all sprinkles and hit "CTRL + L" and then link materials 
- set each sprinkle so that it shares the same material in the materials tab then you will notice they are the same color when editing in the nodes from shading tab 
- now we want to randomize the colors. we use an "object info node" to do this and plug "random" output into "base color" input 
- we will also place a "color ramp" node between object info node and principled bsdf node 
- add colors 
- changing color ramp node from linear to constant will take away the colors being assigned from somewhere within the gradient to making it one solid color from there (i.e. no varying shades, one color or the other) 

donut is le done 

## part 11 -- le animation
### camera framing
- get rid of plane and go to front end view using num pad 1 hot key 
- ctrl + alt + 0 to snap camera to view 
- if we were to select just the donut base and rotate it, we would see that the icing does not rotate with the donut base and that needs to be fixed 
- we need to tell blender that the donut is the "parent object" of the icing. first we select the icing, then we select the parent object (base) using shift + click, then hit "ctrl+p" to parent them together. usually just "object" will work but with unapplied or incorrect scale we might see some rotation issues, in that case use "keep transform" option 
- now they will rotate together 
- we can still move the icing around by itself, but moving the donut will also move the icing. notice the dotted line from icing to donut showing that the icing is parented to the base 
- now we are going to setup the animation to display the donut, look into camera view the with num pad zero hot key and from there we will start making adjustments to setup the animation 
- frame up -- transform and resolution can be adjusted 
- with the camera selected we can change the focal length of it 
- random tip, with camera selected under viewport display, composition guides can be used that will put up a display in the viewport framing 

### playback and frame rates
- animations can be done on timeline of layout but there is also a animations specific tab 
- playback is defined by frames per second. frame rate is displayed in output settings. ex) if i wanted 10 seconds at 24 fps, i would need 240 frames in that 10 second clip. 
- religious war of frame rates. 24 fps vs. 48 fps. hobbit introduced 48 fps, ppl were mad. now there's 60 fps as well. ppl mad at that too. the more fps the more rendering needs to be done
- for donut tutorial we are going to use 30 fps.
- now we are going to hit "I" for "insert keyframe" and the following menu will pop up 
- add location keyframe for donut, move donut, add another location keyframe, play le animation to see donut move from point A to point B
- keyframe the donut rotation
- its better to do this in the animation workspace rather than layout tab
- tutorial instructor prefers top left panel to be a graph editor 
- add keyframes to make donut animation go brrr 
- once we are satisfied with how much brrr the donut goes, we will move on to the next part to add floating particles in the background that will also be going brrRrRrRRRr

## part 12 --- adding floating particles going brrrrr to le animation
- the tutorial instructor says we can skip this section if too hard. this is just a "nice to have" bonus material kind of thing -- floating particles
- we are going to add a plane mesh then go into geometry nodes and click new node for the plane 
- add nodes: distribute points on faces, set position, and random value. random value node changed to vector 
- add a second "set position" node. then shift + left arrow num pad" and then notice in the top left the (1) in paren represents that we are on frame 1. with plane selected, set values of snowflakes positions and hit "I" over the values to set their keyframe for frame 1. 
- "shift + right arrow num pad" and then notice in the top left corner we have now gone to the last frame in the animation, in this case 300. adjust the value of zed on the second position node 
- now when we play the animation, we have an effect of falling particles
- instead of using keyframes, the instructor wants us to use a series of nodes which gives us more flexibility in controlling the falling particles animation. we are going to add "value" + "math" (which should be set to divide) + "combine xyz" nodes 
- adjust values 
- to comment on a node to label it / help remember something about it, with the node selected, hit "ctrl + J" then on the right side under node find the label section to type in whatever you want, then you will see a box around the node with that label 
- now in addition to making the particles fall down, we are going to make them fall down and diagonally to the left -- plug the speed of the snow into the X value on "combine xyz" node to do this. must play with random value node and distribute points density settings in order to get it right to keep snow in the frame the entire time 
- now we would like to make each of the particles move in a way that is not all collective. i.e. right now each particle is moving down and to the left at the same pace. how do we make them move independtly of each other?
- we are going to use "random value" node along with another "math" node set to multiply. now playing with the min and max of the random value node will adjust movement of the snow 
- now we are going to replace the snowflakes with the sprikles that we made and distributed on the icing earlier in the tutorial
- we are going to do this by placing "instance on points" node at the end of our node connections, then drag the sprinkles collection into the node screen and plug it into the new node we just place. check boxes for "pick instance" and "separate children" and "reset children" 
- the sprinkles are really small so we want to adjust the scale up in the "instance on points" node
- we are also going to add a random value node and plug it into the rotation input on "instance on points" node in order to assign random rotation values to each floating sprinkle 
- now to further randomize the rotations, we are going to add a "rotate euler" node, and change to axis agle (rather than euler) then plug the frame value node into the angle input -- we will now see random rotations, but the speed is too fast so we need a math node to cut the speed in half or more than half 
- add math node, play with speed reduction of value until you are happy with the speed of rotating sprinkles 4
- add more randomness to sprinkles with multiply node and random value node plugged in as such: 

## part 13 -- intro to lighting
- we are going to make some nice lighting aesthetics for le donut
- we're going to split screen in layout mode with one screen focused on the active camera view (hot key is num pad 0) and the other screen to select and adjust the lighting 
- play around with position of light to see how it impacts scene
- also zoom in to play around with raidus of light source to see how it impacts the scene 
- our goal here is to do some stuff that will make shadows look as good as possible
- INVERSE SQUARE LAW -- how bright things appear changes drastically depending on how close lamp is to object.
- when you double distance from lamp source, you're actually reducing light by 4x, not 2x
- this law is just something to keep in mind -- basically we are set here once we have our light source in a place and we are satisfied with the basic lighting of the scene
- FILL LIGHTING -- essentially just duplication of light source to fill in lighting. in this example the tutorial instructor wants us to dupliacte lamp and place it diagonally across from the original 
- also take note of lighting in the world properties tab -- this is a default light that comes from all directions, even with no lamp active. notice how changing color to black will make it completely dark 
- also check out render tab, then go down to color management -- we have various options under "look" to change the default color correction. instructor uses high or medium to high for this project 
- CHECKING LIGHT EXPOSURE -- in the same tab (render), also under color management, changing "view transform" to "false color" will give us a heat map type of display which is showing us how much light exposure areas of our objects and particles are getting (side note we never want to see a white color in this heat map, that means we are losing data) 
- RIM LIGHTING -- we want to place a light source to make it so that the rim's of the donut stick out a bit more and do not "blend" into the background. so duplicate the lamp, press "alt + G" to set the light at the 0,0,0 point (dead center of scene), then move it in back of the donut and slightly off to the side in order to enhance the rim lighting 
- "three point lighting" rule -- main, key, fill. does not apply to all situations but it is good lighting setup to use

## part 14 -- compositing
- our donut looks good but can look even better with some compositing. compositing is aka "post processing" -- what are you adding to image after you are pretty much done rendering
- blender has built in compositor
- we are going to click into the compositing tab in the top right, then check the "use nodes" box and our render layeres will pop up, plugged into a composite node 
- ctrl + shift + click any node to add a viewer node and then that will plugin image to background 
- instead of working with nodes on top of that backdrop, split screen, take away backdroup in main screen on compositing tab, then on right hand side edit the highlighted box to "image editor" and then change drop down menu to "viewer node" 

- CHANGING BACKGROUND COLOR
- we want to get rid of the black background -- to do this we go under render properties, and click the box for transparent under "film" ... the changes in the view node screen will not be reflected until you re-render, f12 hotkey to re-render, then black background will be replaced with transparent background 
- to change the color we are going to add two nodes into our compositing nodetree -- "RGB" and "Alpha Over" ... plug them in as follows -- notice on the right hand side we have a solid green color and can no longer see our donut. 
- solid green color is because we are not using the alpha information from render. we need to take alpha from render layers node and put it into factor input of alpha over node. 
- now it is using the alpha but doing so in the wrong direction, inputs need to be flipped on alpha over node 

- CREATING GRADIENTS
- we are going to temporarily disconnect alpha over node from the end viewer and add an "ellipses mask" and "blur" nodes to create a gradient effect. play with various values on the two added nodes to create gradient. instructor recs using fast gaussian. 
- now we have to cut the blur fromt the main viewer and add a "mix" node, then re-arrange some inputs and outputs in order to layer this gradient into the background
- add a mix node. output from elipse mask to blur input to mix. RGB node cuts connection to alpha over node. and input into mix node. mix node output into alpha over input, reconnect output of alpha over into input of end viewer 
- to change the gradient from white/black to white/the color we choose, change the mix node option here from "mix" to "add" 

- SPECULAR GLOW
- adding glow can also be done with compositor
- add highlights, bleed effects, etc.
- glare node can be used -- instructor doesn't like too much.
- instructor wants to blur parts and then apply blur over the top to make it look like glare
- we already have a blur node in our compositing nodetree -- we are going to duplicate the blur node and then take output from main image and put it into input of duplicated blur node. ctrl + shift + click on the duplicated blur node to temporarily cut the connection between alpha over and viewer, in order to see what the duplicated blur node gives us 
- dial back the blur a bit -- 
- what we want to do is find only the reflective parts of the donut to apply the blur to ... we can do this with "render passes" ... go into view layer properties tabs, and then passes subsection
- 
- passes / render passes is very common in 3d. some post processeing steps include exporting each pass and editing each one in photoshop, etc.
- we have diffuse (natural color of material), glossy (reflective light), transmission (glass, semi transparent things), volume (fog, smoke, etc.), and other types of passes
- for this instance where we want to make something more reflective we are going to be using glossy options
- ***note the options above do not match with the video instruction but we are using specular, light for this
- with specular light checked off, ctrl + shift + click on rendered layers -- the right hand side goes blank, because we need to re-render 
- our render turns out really black (this is supposed to happen) 
- output rendered image into blur node input, output that into end viewer -- see result of blured donut 
- duplicate add node, output blur into duplicated add, output alpha over into add input, add output into viewer input 
- super shiny, needs to be less shiny. this can be adjusted with the value on the duplciated add node (turn it down) 

- COLOR GRADING
- color grading -- can be done under color management. this is a whole new topic but instructor will show the basics. we are going to do it in the compositor.
- add color balance node. left wheel correspods to dark tones, middle to mid tones, right wheel to light tones. color balance node must be plugged into compositor. change correction form to "offset/power/slope" 
- play with values of wheels until happy with color
- doing it in compositor vs. in scene. everyone has preferences, figure out your own

- CHROMATIC ABERRATION
- now adding lens distortion between color balance and viewer + composite 
- according to instructor this is not necessary for our donut but he's showing us anyway cuase he thinks its cool
- keep values of both dispersion and distort very low, check mark the fit box to stretch to screen 

- SHARPENING
- easy way to improve any image according to instructor
- add a "filter" node and set it to one of the sharpen options, keep factor amount very small. 
- this was very basics of compositing

- ISOLATING THE GLOW
- drop a threshold to only see bright areas. drop an S curve with "RGB Curves" node 
- with S curve on the RGM Curves node, the dot on the left side is the "contrast side" and the one on the right is the "highlights side" 

## Part 15: Render settings to improve render times
- two ways to render final image
- evee -- fast game engine rendering
- cycles -- slower but "true ray tracing" which results in more realistic results
- can drastically reduce cycles render speed
- this section will be on how to render with both methods

### starting with cycles
- in layout mode, under render properties, choose render engine and set it to cycles
- we want to turn OFF "noise threshold" under "render" in "render properties" as it can complicate the final result according to the instructor 
- we are also turning samples way down to 100 (the instructor says he is doing this to demonstrate what is going on with cycles)
- path traces with cycles: starts noisey, then it becomes more refined and clear. noise is determined by samples. the more samples, the less noisey it becomes. sample count is biggest determining factor on how useable an image is, according to instructor
- we want the least amount of noise as possible in the least amount of time. this is "the game 3d artists are playing"
- instructor recommends turning off clamping and reflective and refractive 
- GO BACK TO REVIEW THIS SECTION. I FOUND IT A BIT HARD TO FOLLOW

### eevee rendering
- real time rendering
- unlike cycles where everything is accurate and ready to go and the goal is to crunch down render time, eevee its fast but you have to turn things on for it to behave correctly
- the biggest section to start with is shadows 
- cube size: all other lamps -- the size of objects where its going to calculate shadows from
- cascade size: sun lamps
- instructor got confused talking about cube size and cascade size, i am also confused
- for shadows cast by the spinkles on to the donuts we need to turn on contact shadows by selecting light in the collections panel in the top right and then going into light settings 
- render settings need to be set for each light source (i think)
- screen space reflections will help eevee renders 
- ambient occulsion will add in darkening in the crevicies -- we might want to add this as well. based on strength of world lighting and then gives ambience. if world lighting is zero this won't do anything 

## Part 16 -- FINAL RENDER SETTINGS
- we want to put all of this together into a video file for the internet
- the way to do this is to save all frames into individual image files (EXR) and then put all images together compiled into one video
- in this example we've done we have 300 frames, so we'd have 300 PNGs that we put together.
- depth of field camera settings can be helpful. 

### final render:
- as stated before, we want to render out a EXR for each individual frame in the animation, then put them all together
- this is defined in output settings in the output properties tab 
- for this render we want to choose the file path location, file type, change color to rgb, color depth to half, keep lossless zip codec, and then finally render 
- when the render is done, we will have 1 EXR file per frame. in this case we have 300 frames, so 300 EXR's will be put into the folder we designate
- now we have to take the 300 EXR's and put them all together. the instructor says rather than doing this in the existing blender project, open up a blank project to do this. on the opening screen hit "video editing" 
- this will open the video sequence editor for us 
- first we need to make sure that the new file resolution is set to the same thing that we rendered on previously
- now we want to add our image sequence. in the video timeline go to "add" and then "image sequence" 
- when adding image sequence find the folder with the EXR frames, be sure to select all frames, then add them
- we now have the animation viewable. we can reverse le animation by going here and clicking le reverse 
- transform can be helpful in dealing with extra space 
- notice there is a gap between the viewable video and how long our image sequence is. that is because the end of this is set to 250 frames while our sequence is 300. change 250 to 300 to resolve this issue 
- instructor says we now need to put filmic color space back on it in order to get back to the correct color profile
- now we will do final output of video. we do this here 
- instructor recs these settings for video output:
- now just render the final animation and then check the folder you designated for the final animation 

## NEXT STEPS
- instructor says now that we have made this donut, we can do more things, such as:
- making cinnamon donut (kek)
- making powdered donut
- a gummy donut
- a croatian donut
- an ice donut
- a holographic sci fi donut
- the bakers dozen (nft art holo donuts by instructor)

- what is good logical next thing to do ? check out "how to learn 3d in 4 weeks" video next