>> I guess for more complex cases, you've got RGBA values to store your >> x/y offsets and scales. You'd just have to watch the accuracy - are >> the gl_Color values 8 bit? > > I'm guessing yes. I'd like to get a definitive answer on that one though. I > notice the possibly values on the RGB color picker sliders go from 1 > 255, > which seems to suggest 8-bit.
Don't go by the colour slider values - I've successfully used >8bit colour values before now (in conjunction with render-in-image set to 32bit). Don't they normally go 0..1 though? I'm not sure how gl_Color is handled at all though - it could be 8 bit or 32, but yes we do need to know :) >> It could get nasty if you're using a few large textures, or if you're >> using a bunch of animated image sources though. If that's the case, >> try my approach, otherwise stick with Alex's image dictionary. > > Definitely. My approach probably doesn't scale particularly well (in number > or size-of-texture terms), but for simple cases where you have a small > number of smallish textures, it's a simple method that works fine. It should scale fairly well I would think (although I can't open the comp here unfortunately to see how it's working..) so long as the texture size is under the hardware limit. The number of textures in the dictionary shouldn't really matter - the slowdown would come from the number of objects, and the amount of extra shader processing for extra objects. Chris > a|x > > > >> >> Chris >> >> >> On 17 March 2010 13:01, Alex Drinkwater <[email protected]> wrote: >>> >>> OK, this works. >>> >>> There's a GLSL shader with 4x Sprite patches inside it. >>> Each Sprite has a different value for the Red channel of it's Color >>> input. >>> The Red channel is read in the Vertex Shader from gl_Color. That value is >>> used to offset the texture coordinates on the X-axis. >>> I also had to scale the X-axis texture coordinates so that they only >>> covered >>> 1/4 of the width of the texture (since it was a strip of 4 different >>> graphics in a horizontal row). The logic would be a bit more complex for >>> a >>> sheet of different textures arranged in a grid, rather than a strip, but >>> the >>> principle would be the same, except you'd need to scale and offset on >>> both >>> X and Y axes. >>> >>> >>> >>> alx >>> >>> >>> >>> >>> >>> >>> >>> On 17 Mar 2010, at 10:06, Chris Wood wrote: >>> >>>> Just to be clear, you can have one shader applied to multiple objects >>>> but it will apply the same texture/effect/whatever to every object. >>>> Fine if you want say lighting applied to everything, but not if you >>>> want separate textures. >>>> >>>> One solution: give each object a unique colour, and use the colour to >>>> select a texture from an array by index. >>>> >>>> Chris >>>> >>>> On 17 March 2010 09:51, thomas pachoud <[email protected]> wrote: >>>>> >>>>> Hi, >>>>> not 100% sure, but I don't think you can use one single GLSL for >>>>> multiple >>>>> objects. You should use one GLSL applied to each objects. In this way, >>>>> each >>>>> objects will apply the same GLSL with his textures and 3D positionning >>>>> and >>>>> lighting information. And if you need to act on full scene, you should >>>>> add >>>>> one GLSL at the end of your pipeline, playing on your 2D final >>>>> rendering. >>>>> On Tue, Mar 16, 2010 at 9:35 AM, George Toledo <[email protected]> >>>>> wrote: >>>>>> >>>>>> I may be wrong, but I don't believe that is possible in QC. What you >>>>>> would >>>>>> need to do is use a separate shader for each object. GLSL in QC does >>>>>> support >>>>>> multiple textures, but I don't think one can assign them to arbitrary >>>>>> objects in the scene. >>>>>> I'm curious about this as well... I've successfully used GLSL in QC to >>>>>> send many different image sources to a shader, and to use the shader >>>>>> to >>>>>> crop, translate and dissolve, but that is in the context of a 2D >>>>>> surface. >>>>>> Is there a downside to putting each object in a separate GLSL macro, >>>>>> and >>>>>> using distinct textures for each in your scenario? You can always >>>>>> connect >>>>>> the join the lighting of each (or any other parameter) with insert >>>>>> splitters, so your multiple shaders can look cohesive in the scene >>>>>> when >>>>>> you >>>>>> move a light source (or whatever). >>>>>> -George Toledo >>>>>> >>>>>> On Mon, Mar 15, 2010 at 7:11 AM, luca palmili <[email protected]> >>>>>> wrote: >>>>>>> >>>>>>> Hi to all, >>>>>>> my scene is composed by N objects (o1, o2..., oN), each of them has >>>>>>> got >>>>>>> one different texture (t1, t2, ..., tN). How can I render all the >>>>>>> objects in >>>>>>> a single GLSL shader? I mean: if I pass my N texture as uniform >>>>>>> parameters >>>>>>> to the GLSL shader, how can I tell to the GLSL shader to use >>>>>>> texture_1 >>>>>>> for >>>>>>> object_1, texture_2 for object_2, etc...? >>>>>>> Thank you! >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Do not post admin requests to the list. They will be ignored. >>>>>>> Quartzcomposer-dev mailing list >>>>>>> ([email protected]) >>>>>>> Help/Unsubscribe/Update your Subscription: >>>>>>> >>>>>>> >>>>>>> >>>>>>> http://lists.apple.com/mailman/options/quartzcomposer-dev/gtoledo3%40gmail.com >>>>>>> >>>>>>> This email sent to [email protected] >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Do not post admin requests to the list. They will be ignored. >>>>>> Quartzcomposer-dev mailing list >>>>>> ([email protected]) >>>>>> Help/Unsubscribe/Update your Subscription: >>>>>> >>>>>> >>>>>> >>>>>> http://lists.apple.com/mailman/options/quartzcomposer-dev/thomas.pachoud%40gmail.com >>>>>> >>>>>> This email sent to [email protected] >>>>> >>>>> >>>>> >>>>> -- >>>>> Thomas Pachoud >>>>> ingénieur multimédia IMAC >>>>> www.creapach.fr >>>>> >>>>> _______________________________________________ >>>>> Do not post admin requests to the list. They will be ignored. >>>>> Quartzcomposer-dev mailing list >>>>> ([email protected]) >>>>> Help/Unsubscribe/Update your Subscription: >>>>> >>>>> >>>>> http://lists.apple.com/mailman/options/quartzcomposer-dev/psonice%40gmail.com >>>>> >>>>> This email sent to [email protected] >>>>> >>>> _______________________________________________ >>>> Do not post admin requests to the list. They will be ignored. >>>> Quartzcomposer-dev mailing list >>>> ([email protected]) >>>> Help/Unsubscribe/Update your Subscription: >>>> >>>> >>>> http://lists.apple.com/mailman/options/quartzcomposer-dev/the_voder%40yahoo.co.uk >>>> >>>> This email sent to [email protected] >>> >>> >>> > > _______________________________________________ Do not post admin requests to the list. They will be ignored. Quartzcomposer-dev mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/quartzcomposer-dev/archive%40mail-archive.com This email sent to [email protected]
